Pay What You Want / Name Your Own Price
In at least one marketplace, at least once, buyers have the option to choose how much to pay for these games.
The first video game about Pay What You Want / Name Your Own Price was released on January 18, 2009.
Anyone sensible selling games like this usually sets the minimum price to 1$ or similar to cover actual transaction fees and actually make some out of it rather than having to pay transaction fees and never get anything themselves. There's been reports of the sellers actually paying large amounts just to pay up for the transaction fees due to too low minimum price rather than getting any money themselves.