Theres indeed a reverse auction. (source: Wikipedia)
A reverse auction is a type of auction in which the roles of buyer and seller are reversed. In an ordinary auction (also known as a 'forward auction'), buyers compete to obtain goods or services by offering increasingly higher prices. In a reverse auction, the sellers compete to obtain business from the buyer and prices will typically decrease as the sellers underbid each other.
Dont have idea if someones using this up since most sellers are using that ordinary auction set-up but you can start a reverse one anytime.
