People from my university had just recently created a startup with similar mechanics, based in Poland -- it has English interface too, though no support for other currencies yet.

http://clicxs.com/how-does-it-work/

Basically, you pay a small amount of money to uncover a price of a given item, decreasing it as a byproduct. For instance, if a price is 50 PLN, uncovering a price (which costs 2.50 PLN) decreases it by 1 PLN. The more people uncover the price, the cheaper it gets, until someone actually buys it.

1 PLN is about 0.35 USD, by the way.