2005 e53 4.8l jumped time..should I get a used engine?

[Feltsandel]

My x5 4.8l n62 went low on oil. Tensioner most likely stopped doing its job and it jumped out of time. It won't run. The local shop looked at it and they say it's gonna be 6000 to pull the engine and overhaul.....and also do the valve seals which were already leaking before hand(a 3500 job in it self from what I understand) . The vehicle is in really great shape otherwise. I'm not sure what to do here. Does anyone have any experience with this? And might they know of a a place that has a used engine? The shops in Virginia do not.
Thanks for any replays
Cheers