The eBay marketplace helps buyers and sellers find the best price for a product through auction-style listings and competing offers. You may need to change the price of an item you list on eBay to be sure you're making as much money as you should.EBay places some restrictions on price changes for auctions with bids or fixed-price listings with past purchases.he eBay marketplace helps buyers and sellers find the best price for a product through auction-style listings and competing offers. You may need to change the price of an item you list on eBay to be sure you're making as much money as you should.