You had a contract that was clearly stated, which was agreed to by the customer and he/she must have also agreed to the TOS. I don’t understand why you would feel that you are at fault. Since you did not breach your contract in any shape or form, it’s legally binding. If you’re worried about the business ethics side, he’s in the wrong. Simple.

You know what? There are two parts to this: first, you are absolutely in the right since you posted your Terms Of Service and the customer agrees to the TOS by doing business with you, meaning you have a contract, and

Seventy-five bucks is too cheap. I’d have held his feet to the fire for the full fee. However, you made the sale, and have learned a valuable lesson.

- Stuart

***Note***
I posted this answer in another category too. sounds like a misunderstanding… it was all there in your TOS, if they didn’t like it (or didn’t read it) it’s their problem. $75 for a static site isn’t bad, I guess. It’s not $365, but it’s some cash in your pocket. If he still doesn’t pay up, sic the DCMA on him!

* Even though Beef Stuart gave me a thumb’s down… he has a point.