Nope, 0.5% is dire. Fix your product.
This is just a shot in the dark, but I have a feeling that it also depends on your target market: You mention a -L-10 pricetag earlier.
However, more people may feel that a game is 'worth' $10 to them and shell out than if the identical game would be $25... I would expect the lower price game to have a higher conversion rate (although the higher priced game may still net more profit for its creators, despite less sales).
Unless your charging the same as well, you're still comparing apples and oranges.