diff --git a/src/lib/server/collection-confirm-service.test.ts b/src/lib/server/collection-confirm-service.test.ts
index 1691168..c43580b 100644
--- a/src/lib/server/collection-confirm-service.test.ts
+++ b/src/lib/server/collection-confirm-service.test.ts
@@ -350,11 +350,9 @@ describe("updateOrderItemCost", () => {
     expect(typeof entry.ts).toBe("string");
 
     // Returned row carries the new cost price (mock resolution merges
-    // the patch into the existing row). `ConfirmRow` is the consumer-
-    // facing shape and omits `cost_price` (the raw PB record has it),
-    // so cast to read the field the test is asserting on.
+    // the patch into the existing row).
     expect(result.id).toBe("row-1");
-    expect((result as { cost_price?: number }).cost_price).toBe(50);
+    expect(result.cost_price).toBe(50);
   });
 
   it("is a no-op when the new cost equals the current cost (no write, no note)", async () => {
@@ -412,6 +410,28 @@ describe("updateOrderItemCost", () => {
     expect(parsed[1].actorName).toBe("sj");
     expect(parsed[1].body).toEqual({ prevCost: 45, newCost: 50 });
   });
+
+  it("propagates errors from pb.collection.getOne", async () => {
+    const failingGetOne = vi.fn().mockRejectedValue(new Error("not found"));
+    const dummyUpdate = vi.fn();
+    const admin = {
+      collection: vi.fn().mockReturnValue({
+        getOne: failingGetOne,
+        update: dummyUpdate,
+      }),
+    };
+    vi.mocked(getAdminPocketBase).mockResolvedValue(admin as never);
+
+    await expect(
+      updateOrderItemCost("row-1", {
+        cost_price: 50,
+        actor: { id: "u-1", name: "sj" },
+      }),
+    ).rejects.toThrow("not found");
+
+    expect(failingGetOne).toHaveBeenCalledWith("row-1");
+    expect(dummyUpdate).not.toHaveBeenCalled();
+  });
 });
 
 describe("stubs for plan task 5", () => {
diff --git a/src/lib/server/collection-confirm-service.ts b/src/lib/server/collection-confirm-service.ts
index 4c3f22b..c5fda16 100644
--- a/src/lib/server/collection-confirm-service.ts
+++ b/src/lib/server/collection-confirm-service.ts
@@ -33,6 +33,7 @@ export type ConfirmRow = {
   order_qty?: number;
   qty_collected?: number;
   quantity?: number;
+  cost_price?: number | null;
   item_status?: string;
   problem_flag?: boolean | null;
   problem_type?: string | null;
@@ -227,24 +228,24 @@ export async function listCollectedItems(): Promise<ConfirmRow[]> {
  */
 export async function updateOrderItemCost(
   id: string,
-  body: { cost_price: number; actor: ConfirmActor },
+  args: { cost_price: number; actor: ConfirmActor },
 ): Promise<ConfirmRow> {
   const pb = await getAdminPocketBase();
   const collectionName = getOrderItemsCollectionName();
   const existing = await pb.collection(collectionName).getOne(id);
   const prevCost = (existing as { cost_price?: number | null }).cost_price ?? null;
-  if (prevCost === body.cost_price) {
+  if (prevCost === args.cost_price) {
     return existing as ConfirmRow;
   }
   const newNotes = appendCostNote(
     (existing as { notes?: string | null }).notes ?? null,
-    body.actor,
+    args.actor,
     prevCost ?? 0,
-    body.cost_price,
+    args.cost_price,
   );
   const updated = await pb
     .collection(collectionName)
-    .update(id, { cost_price: body.cost_price, notes: newNotes });
+    .update(id, { cost_price: args.cost_price, notes: newNotes });
   return updated as ConfirmRow;
 }