Quoted from NiftyLED:Im in this machine for X
Doesn't matter what you're into it for. Matters what you told him it was going to cost. It's not the customer's job to make sure you run a profitable business. Every single business since the beginning of time has lost money at least once due to an oops. Looks like it's your turn.
Eat the loss, learn from it, pray you haven't permanently tarnished your reputation, move on.