can i update stock when same items are purchased with same SKU, but price and supplier are changed?

Yes, Jacob. You can maintain the same SKU for an item with varying prices and suppliers in QuickBooks Online (QBO).

When making a new purchase, you can create a new Bill and select the existing Inventory Product Service item. From there, you'll have to manually adjust it's rate within the transaction.

Here's how to do it:

1. Navigate to the +Create in the top left corner of your dashboard.
2. Select Bill if you plan to pay later or Expense if you've already paid.
3. Complete the top section with the following details from your new supplier.
4. In the Product/Service column, select the existing inventory item (Memory card, same SKU).
5. Enter the Quantity being purchased (5).
6. Apply the new Rate/Cost per item.

Once done, the total amount will automatically calculate (Quantity x Rate) and update the Quantity (QTY) on hand in your existing inventory item in QBO.

You can also run a report like Inventory Valuation Detail to monitor stock showing transaction history, item quantity, and value with  First-In, First-Out (FIFO) method calculations after each purchase.

Feel free to reply to this post if you need further assistance.