I think ingots are the only way though via events.

At the top of my head, I can't think of him being in an event where you c*e coupons or collect points for him. I might be wrong, cause there may be 1 or 2 events possibly if other forum members can correct me on that. But I think he's an ingots only ninja for now.

Either get a job that gives a pay check, rob a bank, steal from your parents credit cards, or basically anything that gives you money or monetary value that can be paid to this game. ;P

Sorry, but that's the only way you can get ingots.