A compression test should help confirm the above diagnosis... also, you can drain the oil, and remove the oil pan side sump, and look for shrapnel inside. The pan should be absolutely free of debris. If you find a bunch of metal pieces floating around... that may confirm Dux's suspicion.
Either way, $1k for a good spare engine & tranny is a great deal. If that were anywhere near me, I'd buy it just to have as a spare, lol!