Here's some discussion...8k for a new Cayenne S motor? How cheap are these made? And you can't
rebuild an early car 2.4L 145hp at a shop for under 12-15k? Granted , the rebuilds don't generally seize up after 4 years...
I would check current prices for that year deduct the 8k and the cost of install then reduce some more. You would have a pretty good car...for 2 years...