Accounts with an eBay Store Subscription can offer eBay buyers a multi-buy discount if they purchase multiple quantities of the same item at once.
Important note: eBay's API may take up to 15 minutes to register volume pricing changes made with 3Dsellers. Please allow some time for multi-buy discounts to appear on live eBay listings.
Edit bulk discounts in the listing editor
When editing a listing, navigate to Selling Details
Enable the Volume Pricing option near the bottom of the page
Then, add and manage discounts based on the quantity purchased