I'm surprised Marco is billing $1/month in 3 month intervals... I'd have just billed $12/year.

$12 is hardly a large payment chasm for a customer, particularly if you've already told them that they're not going to get anything particularly extra for their subscription and they're still interested.

But it also makes the fixed-fee on the transaction a lower %age of the total sale and of course from a cash-flow perspective you have a full 12 months income in the bank now.