I suppose they just never sold well because anyone wanting that level of control with that bulk just went for 4x5 with a rollback adapter?
Lenses for under $100, bodies for $100-150, just make sure there's a battery holder in there because they look to go for $150 separately.
Full kits for $300-400. Look for a guy on fleabay called 'astrosmith22', he sells a lot of GX stuff. I've bought a lot of Toyo stuff from him, he packs well and ships fast and it's mostly near new.
The other option for TS on 35mm, without going to the ridiculous prices of Canon's (even the RokiBowYang TS ain't exactly cheap) are Pentacon Six lenses on adapters.
The widest you get are 50mm Zeiss (sharp, $100-150), 45mm Soviet (hit and miss, $50-100), or 30mm fisheye ($100-200) and you can get a tilt OR shift adapter for $100 (mostly arax/arsat).
There are a few tilt AND shift adapters for $350-400 (arax/arsat, zörk, mirex). But when I started using them on my digital I only bothered for a while, then gave up and bought a P6, I can always crop the film...