Yeah have people load up a $10 into there account and then making $1 purchases seems a good idea. Although the current transaction fee with Blockchain.info/Wallet on frugal setting for transactions is only $0.01. Which is a lot better than PayPal or Visa.
The difference being that as a merchant, _I_ pay the processing fee. With Bitcoin, the customer pays a fee in addition to me (I pay BitPay as well). I'm curious to see how this goes, I'm trying to experiment being a BTC-only merchant, and it's quite a difference to offer something for sale and then expect the customer to pay a transaction processing fee. Normally this would be rolled into the price, but I cannot pay this on their behalf.