It all depends on how much you really like this car. I personaly would take the 12k and start shopping around. Its not like the car had low miles and theres other stuff that it looks like it needs. Think about it $2900(engine)+$500(tires)+Air pump and what ever time & money it takes to get it all done. If you need a car now out of necessity you gotta do what you gotta do, but if you connect with the car I don't think anyone'll blame you if want to keep the project going.