diff --git a/src/controllers/api/giftingController.ts b/src/controllers/api/giftingController.ts
index 55865cee..9a532776 100644
--- a/src/controllers/api/giftingController.ts
+++ b/src/controllers/api/giftingController.ts
@@ -11,13 +11,13 @@ import {
 import { getAccountForRequest, getSuffixedName } from "@/src/services/loginService";
 import { handleStoreItemAcquisition } from "@/src/services/purchaseService";
 import { IOid } from "@/src/types/commonTypes";
-import { IInventoryChanges, IPurchaseParams } from "@/src/types/purchaseTypes";
+import { IInventoryChanges, IPurchaseParams, PurchaseSource } from "@/src/types/purchaseTypes";
 import { RequestHandler } from "express";
 import { ExportBundles, ExportFlavour } from "warframe-public-export-plus";
 
 export const giftingController: RequestHandler = async (req, res) => {
     const data = getJSONfromString<IGiftingRequest>(String(req.body));
-    if (data.PurchaseParams.Source != 0 || !data.PurchaseParams.UsePremium) {
+    if (data.PurchaseParams.Source != PurchaseSource.Market || !data.PurchaseParams.UsePremium) {
         throw new Error(`unexpected purchase params in gifting request: ${String(req.body)}`);
     }
 
diff --git a/src/services/purchaseService.ts b/src/services/purchaseService.ts
index 4fb5bb2d..56cc9ed7 100644
--- a/src/services/purchaseService.ts
+++ b/src/services/purchaseService.ts
@@ -11,7 +11,13 @@ import {
 import { getRandomWeightedRewardUc } from "@/src/services/rngService";
 import { applyStandingToVendorManifest, getVendorManifestByOid } from "@/src/services/serversideVendorsService";
 import { IMiscItem } from "@/src/types/inventoryTypes/inventoryTypes";
-import { IPurchaseRequest, IPurchaseResponse, SlotPurchase, IInventoryChanges } from "@/src/types/purchaseTypes";
+import {
+    IPurchaseRequest,
+    IPurchaseResponse,
+    SlotPurchase,
+    IInventoryChanges,
+    PurchaseSource
+} from "@/src/types/purchaseTypes";
 import { logger } from "@/src/utils/logger";
 import worldState from "@/static/fixed_responses/worldState/worldState.json";
 import {
@@ -52,7 +58,7 @@ export const handlePurchase = async (
 
     const prePurchaseInventoryChanges: IInventoryChanges = {};
     let seed: bigint | undefined;
-    if (purchaseRequest.PurchaseParams.Source == 7) {
+    if (purchaseRequest.PurchaseParams.Source == PurchaseSource.Vendor) {
         let manifest = getVendorManifestByOid(purchaseRequest.PurchaseParams.SourceId!);
         if (manifest) {
             manifest = applyStandingToVendorManifest(inventory, manifest);
@@ -69,18 +75,12 @@ export const handlePurchase = async (
             }
             if (!config.dontSubtractPurchaseCreditCost) {
                 if (offer.RegularPrice) {
-                    combineInventoryChanges(
-                        prePurchaseInventoryChanges,
-                        updateCurrency(inventory, offer.RegularPrice[0], false)
-                    );
+                    updateCurrency(inventory, offer.RegularPrice[0], false, prePurchaseInventoryChanges);
                 }
             }
             if (!config.dontSubtractPurchasePlatinumCost) {
                 if (offer.PremiumPrice) {
-                    combineInventoryChanges(
-                        prePurchaseInventoryChanges,
-                        updateCurrency(inventory, offer.PremiumPrice[0], true)
-                    );
+                    updateCurrency(inventory, offer.PremiumPrice[0], true, prePurchaseInventoryChanges);
                 }
             }
             if (!config.dontSubtractPurchaseItemCost) {
@@ -166,18 +166,15 @@ export const handlePurchase = async (
     );
     combineInventoryChanges(purchaseResponse.InventoryChanges, prePurchaseInventoryChanges);
 
-    const currencyChanges = updateCurrency(
+    updateCurrency(
         inventory,
         purchaseRequest.PurchaseParams.ExpectedPrice,
-        purchaseRequest.PurchaseParams.UsePremium
+        purchaseRequest.PurchaseParams.UsePremium,
+        prePurchaseInventoryChanges
     );
-    purchaseResponse.InventoryChanges = {
-        ...currencyChanges,
-        ...purchaseResponse.InventoryChanges
-    };
 
     switch (purchaseRequest.PurchaseParams.Source) {
-        case 1: {
+        case PurchaseSource.VoidTrader: {
             if (purchaseRequest.PurchaseParams.SourceId! != worldState.VoidTraders[0]._id.$oid) {
                 throw new Error("invalid request source");
             }
@@ -186,10 +183,7 @@ export const handlePurchase = async (
             );
             if (offer) {
                 if (!config.dontSubtractPurchaseCreditCost) {
-                    combineInventoryChanges(
-                        purchaseResponse.InventoryChanges,
-                        updateCurrency(inventory, offer.RegularPrice, false)
-                    );
+                    updateCurrency(inventory, offer.RegularPrice, false, purchaseResponse.InventoryChanges);
                 }
                 if (purchaseRequest.PurchaseParams.ExpectedPrice) {
                     throw new Error(`vendor purchase should not have an expected price`);
@@ -207,7 +201,7 @@ export const handlePurchase = async (
             }
             break;
         }
-        case 2:
+        case PurchaseSource.SyndicateFavor:
             {
                 const syndicateTag = purchaseRequest.PurchaseParams.SyndicateTag!;
                 if (purchaseRequest.PurchaseParams.UseFreeFavor!) {
@@ -244,22 +238,16 @@ export const handlePurchase = async (
                 }
             }
             break;
-        case 7:
+        case PurchaseSource.Vendor:
             if (purchaseRequest.PurchaseParams.SourceId! in ExportVendors) {
                 const vendor = ExportVendors[purchaseRequest.PurchaseParams.SourceId!];
                 const offer = vendor.items.find(x => x.storeItem == purchaseRequest.PurchaseParams.StoreItem);
                 if (offer) {
                     if (typeof offer.credits == "number" && !config.dontSubtractPurchaseCreditCost) {
-                        combineInventoryChanges(
-                            purchaseResponse.InventoryChanges,
-                            updateCurrency(inventory, offer.credits, false)
-                        );
+                        updateCurrency(inventory, offer.credits, false, purchaseResponse.InventoryChanges);
                     }
                     if (typeof offer.platinum == "number" && !config.dontSubtractPurchasePlatinumCost) {
-                        combineInventoryChanges(
-                            purchaseResponse.InventoryChanges,
-                            updateCurrency(inventory, offer.platinum, true)
-                        );
+                        updateCurrency(inventory, offer.platinum, true, purchaseResponse.InventoryChanges);
                     }
                     if (offer.itemPrices && !config.dontSubtractPurchaseItemCost) {
                         handleItemPrices(
@@ -275,7 +263,7 @@ export const handlePurchase = async (
                 throw new Error(`vendor purchase should not have an expected price`);
             }
             break;
-        case 18: {
+        case PurchaseSource.PrimeVaultTrader: {
             if (purchaseRequest.PurchaseParams.SourceId! != worldState.PrimeVaultTraders[0]._id.$oid) {
                 throw new Error("invalid request source");
             }
diff --git a/src/types/purchaseTypes.ts b/src/types/purchaseTypes.ts
index 8cb92ccc..0ccff176 100644
--- a/src/types/purchaseTypes.ts
+++ b/src/types/purchaseTypes.ts
@@ -10,14 +10,42 @@ import {
     ICrewMemberClient
 } from "./inventoryTypes/inventoryTypes";
 
+export enum PurchaseSource {
+    Market = 0,
+    VoidTrader = 1,
+    SyndicateFavor = 2,
+    DailyDeal = 3,
+    Arsenal = 4,
+    Profile = 5,
+    Hub = 6,
+    Vendor = 7,
+    AppearancePreview = 8,
+    Museum = 9,
+    Operator = 10,
+    PlayerShip = 11,
+    Crewship = 12,
+    MenuStyle = 13,
+    MenuHud = 14,
+    Chat = 15,
+    Inventory = 16,
+    StarChart = 17,
+    PrimeVaultTrader = 18,
+    Incubator = 19,
+    Prompt = 20,
+    Kaithe = 21,
+    DuviriWeapon = 22,
+    UpdateScreen = 23,
+    Motorcycle = 24
+}
+
 export interface IPurchaseRequest {
     PurchaseParams: IPurchaseParams;
     buildLabel: string;
 }
 
 export interface IPurchaseParams {
-    Source: number;
-    SourceId?: string; // for Source 1, 7 & 18
+    Source: PurchaseSource;
+    SourceId?: string; // VoidTrader, Vendor, PrimeVaultTrader
     StoreItem: string;
     StorePage: string;
     SearchTerm: string;
@@ -25,10 +53,10 @@ export interface IPurchaseParams {
     Quantity: number;
     UsePremium: boolean;
     ExpectedPrice: number;
-    SyndicateTag?: string; // for Source 2
-    UseFreeFavor?: boolean; // for Source 2
-    ExtraPurchaseInfoJson?: string; // for Source 7
-    IsWeekly?: boolean; // for Source 7
+    SyndicateTag?: string; // SyndicateFavor
+    UseFreeFavor?: boolean; // SyndicateFavor
+    ExtraPurchaseInfoJson?: string; // Vendor
+    IsWeekly?: boolean; // Vendor
 }
 
 export type IInventoryChanges = {