Replacing the motor in a WK2 diesel is not uncommon. We have covered the failure of the bottom end bearings in these several times. There are some known issues witht he design and combination of these faults and the eight speed transmissions are causing the failure.
Once that has happened, the options before you are walk away, second hand engine or reconditioned engine. if you go with the reconditioned engine you are looking at $22K (subject to change)
But what do you get for your $22K