They are plentiful up here. I advertise now and then that I'll buy VW diesel engines, paying from $25-500.
I'll usually pay about $200 for a running 1.6td, but I've paid as low as $100. 1.9's are a bit more... I just paid $100 for a longblock, who knows what I'll find in that thing. I usually pay 3-400 for a running 1.9.
Over here, there are still lots of running VW diesels available for $4-600. They have bad breaks, rust and are basically beat. I don't have the time & space to take a whole car, but when I'm done outfitting my garage I may start doing that. Drop the front clip and have the car towed away.
Right now, I keep my eyes peeled for 93-98 VW diesels for ~$500. When I come across one, I have a VW shop that will pull the engine for me and they keep the car.
Right now I've got 2 1.6tds, and 2 1.9tds in my garage at home. After Xmas, I'll pull them apart and part them out here. That's my "slush fund" for garage projects.
I've thought about selling complete engines to you guys in the states, but I'd hate to crate up a running engine, then have someone recieve it, tear it apart and find issues. By tearing them down, I'm able to take good pictures of the condition, and let folks decide based on that.