[quote name='bludd']The psn points are usually $20?[/QUOTE]
There's no such thing as PSN points... The PSN cards are funds, if you buy the $20 cards, you're getting $20 for PSN. All of the purchases are in $, it's not a point system.
In this case, if you're buying TWO $20 cards, then you're paying $34, which means you're getting $6 free and if you're in a PSN sharing group, that's SIX $4.99 games (6 pennies leftover) or THREE $9.99 games (3 penny leftover). And since you're in a group, the 6 pennies in the $4.99 becomes 30 cents, the 3 penny in the $9.99 becomes 15 cents.
Thanks OP for the heads up, need to get few...