Drupal 7 auction module or something
Auction module provides auction functionality. Commerce integration is an option.


  Structure: Auctions are entities with start / end date, starting
  price, minimum price and instant buy price. Auction content type with
  auction reference field is created upon installation.


or

Commerce Auction module lets you create auction/reverse auction websites using drupal commerce. see the Demo

Features


Allows creating auctions and reverse auctions using drupal commerce
Automatic auction timeout extension
Automatically adds auctioned product to the winner's shopping cart
By default disables remove and edit quantity fields of auctioned products in shopping cart
Global and per-auction bid limits (like uc_auction)
Lists bids using views