We advise against manually editing product data in Trade Me, as this is likely to cause issues with the feed data, and your changes will be overridden at every automatic feed upload.
If you want to change the quantity on Trade Me without changing the quantity in your ecommerce store, we recommend that you create a promotion using the Promotions Manager feature in our system.
Inventory is best managed directly in your eCommerce Store.
More information about promotions is available under the Pricing and Promotions section.