I have a friend who sells debtor data for a living. He literally sells Excel spreadsheets of debtor data (name, address, SSN, amount owed, etc) to collections agencies for $5k-$25k a pop. He makes mid-six figures doing it. The quality of the data is what commands the price. He said the least desirable debt are debts older than a year and medical debt. He can't even give that crap away.

Also, if you're ever called by a collections agency, you should ask them to provide proof that they actually hold the debt you're obligated to pay. In some cases they've just bought the data, usually from another collections agency who couldn't collect, and they're trying to shake you down. Once you use the magic phrase "provide proof" they give up and stop hassling you, because they have no proof.

I used to worked at Wells Fargo and my friend in sales said the mortgage underwriters typically didn't blink at medical debt.

I wonder what would happen if it was widespread knowledge that the smart money was in never paying it.