When I was living for a summer outside NY City there was variation on the speaker scam.
You'd be walking along the sidewalk, and couple of fellows would pop the trunk of their car and offer you a pair of big speakers for a good price. All sorts of stories were used about why they were selling them. You could look at them, examine them. Anything you wanted. If you had a stereo you could test them even (but who walks around with a stereo?). You'd get them home and they'd work fine even.
The scam was that they were buying cheap speakers, legitimately. Even getting a volume discount from the store. But they were charging 2x and 3x what they worth, and were counting on the out-of-town rubes believing that they were "hot", and therefore being sold at a steep discount. Part of the schtick was that they insisted on giving everyone a receipt. And of course the more the scammers insisted on doing the paperwork for the goods sold from the trunk of the car, the more their 'customers' were convinced by the schtick.
The cops tried to shut them down, but they weren't doing anything really illegal. They paid their taxes, and had the paper work to prove it. They plugged the meter. They weren't vending on the sidewalk, so there was some doubt whether the city's vending laws even applied. And if the scammers were cited they just paid the fine because it was small, and they figured it was cheaper to pay it than to fight it.
The only thing they were guilty of was taking advantage of the tourists' greed.
Thats pretty much a mobile version of the "going out of business" sale. Some places have been going out of business for decades now, wonder when they are finally going to close up shop