So, PayPal has a micropayment system as well as a regular payment system. The micropayment fee is 5% + $0.05 while the normal fee is 2.9% + $0.30. For payments below $12.00, it makes sense to use the micropayments system and the normal system above that level.
Here’s the rub – you can only set up your PayPal account for one or the other. I’m working on a WordPress PayPal plugin, but I’d like to have that plugin work with micropayments without forcing all of my other PayPal transactions to go through that fee structure. Oh well.