No this is not expensive, it's what all payment processors charge, and until you do 10k a month, it's so much better an option than anything else that everybody should just stick to a payment processor when launching small services. There is absolutely no way anyone on a solo budget/time frame can afford to roll their own solution (not even doing CC processing through a CC gateway).
(and yes I do realize that it hurts to see those costs the first few times you make a sale, getting upset over costs like this is the hallmark of the noob internet businessman - it'll pass. Wait until you get your first bill for a nonsense legal issue or pay a 100k settlement for which you know you're in the right but for which you also know that going the length will cost more. Those are the times when it will hurt even more than this.)