Just for clarification, if you buy 5 games the games with the third and fourth highest value are free, so it is not necessarily the cheapest games.
(i.e. $49.99, 39.99, 34.99, 29.99, 4.99; the 34.99 & 29.99 games would be free, and the $49.99, 39.99 & 4.99 games are paid for.)
Also of...