HELP I need a reliable used car

Well, without the fix you owe 12K on a car that is worth 1300 bucks

For an extra 1000, you can owe 12K on a car that is worth 6000 bucks

Seems like a no brainer, but like you said, then what?
I would see if you couldnt get them to throw in some kind of WRITTEN warranty

If they don't...i might sell it