Those Tdi motors are so simple to refurbish, why would you pay that?
Obviously if you need it quickly you may have no choice but I reckon doing it yourself takes no more than 2 weekends (3 if you take your time and to allow for machining).
Alright, not everyone has the know how or is even interested in getting their hands dirty, but if you do/are then diy is the best.
You can get the short motor built by the machining shop so that's a key part of the build done anyway.
Really, other than the weight (its heavy), it was one of easiest engine strip and rebuilds I've ever done. The tolerances are immense compared to the bike engines I normally play with.
I appreciate you need some special tools like an engine crane and an engine support stand but you can hire them.
Beware, if someone is refurbishing an engine to make money then they are only going to do the bare minimum to it, not the full "whether it needs it or not" that only you would do.