Ok my family is also in the auto repair business, and has been for the last 95 years. Think of having a customer with a one of a kind totally made custom car that comes in and a hard part, something crucial to that car, needs to be made by a tool and die company and it costs around 10k to have it made. I doubt you would want to front that much out for an overhead expense, so you would most likely ask for at least a majority, if not all, of that cost up front before you would have that one of a kind part made. That’s the way it is with custom chips, if he made them and you backed out on the order there’s no way he could recoup his investment, just like if you got stuck with a 10k part that would fit no other car in existence. I’m sure you understand now why the $$ are due up front.