It's not normal for businesses operating completely within the law to not give a customer a receipt for large cash transactions. I'm sure this guy would like to hide the fact he did that much cash business, and if he bought it for cash and flipped it for cash, there is absolutely no record of those transactions for the taxman to go after. Giving you a receipt that may someday be looked at by an IRS auditor, who then matches receipts with vendor records to see if those transactions actually took place, could be a problem for this dealer.

You should have asked for a receipt at the time. He may have said that issuing a receipt would mean a higher price, and a dead giveaway that the guy is cooking the books. Any time someone operates a business using questionable or 'shady' practices, you'd be right to be nervous about whether or not what you were sold is legit. Now, I'm not saying the bar is bad. But if it is, paying cash and having no receipt is not protecting yourself.