I used to have a 1st edition 24mm TS-e that nowadays can often be had for just under $700 on ebay in decent condition. It's still a stellar performer, you just have to deal with more vignetting and CA at extreme shifts, both correctable in post if you have the patience. Distortion is also pretty well controlled in the lens. Having shot both the mark I and mark II, I can say that there is a difference in sharpness, but not noticeable until you go past 100% crops. My only major gripe is that the SOOC colors from the original lens can be... how can I put it... somewhat dated? It's hard to explain, it's like the colors in old architecture photos of the 80s shot with something like Velvia slide film, but I manage to use it successfully for shots like below.
If you can swing for a mark II 24mm TS-e though... It's quite an upgrade =)
Here's a link to one on fleabay: