...I don't see how you deduced from Jeff's statment that half an engine job is worth $5K.
Good question...I had to think about it again

The current "offer" is 2000 hours on the engine @ 20K...which people think is too high.
If the same plane went for 15K, it's perceived to be a good deal.
Other people state that if the engine had 1000 hours on the engine, then it might be worth $20K
So I thought the difference was 1000 hours (or ~ half of TBO) which was being evaluated at $5K
This seems to make sense as an O/H is in the range of $10K