We have a TMC pontoon (built in Poskin, Wi) and bought it used with a 50 Honda. It's 24.5 ft, 2 toons and a nice interior. Not lavish, but nice and clean. Since we already had a ski boat, we did not feel like we needed any more "omph" than the Honda would provide.
The pontoonie is a 1998, and it looks almost brand new. Just take care of it an it will last. Honda engine has given no problems at all. Interior is original, has a treated plywood deck with no soft spots. But we have gone through 3 covers. Dont ride hard-put away wet.
Bottom line is if you use it alot with kids (as a swim raft) and it's your only boat, then spend more. If it's not, find a good used one an it can fill the bill.