Businesses are not obligated to accept payment in the form of pennies.
Businesses (and government, especially, for that matter) are obligated to take cash *for debts*. A business is perfectly free to define what they deem acceptable for *payment*, however. Wampum, sea-shells, old Reader's Digest, whatever.
This guy *owes* them $526 bucks, so he is free to pay cash. I'm NOT advocating what this guy is doing, just pointing out the difference.