If youre looking for collection purposes (ie. not to use more along the lines of investment purposes), custom made is the best route. Production stuff tends not to appreciate. Even some custom stuff, wont appreciate. However, as most collector will tell you, never count on stuff appreciating. Until the 80s (who said those 80s Ninja Movies never did any good), even Japanese Swords could still be found relatively cheap. However, a good custom built sword, can put you back a few grand. Though deals can be found with newer smiths in Japan, and there are quite a few smiths in the US, that could probably give you a reasonable deal. However, as far as production kats go Rick Barret is producing some nice semi-custom pieces that are a step above regular Paul Chen stuff. Bugei's stuff has a decent reputation, as they inspect all the stuff they get. However, at the prices both are charging, I would personally save for a custom. Now, gunto's, WWII era japanese swords, can often be found for under a grand still, sometimes real cheap depending on quality. Some can be quite nice. Check out local arm shows. Dont know if you have anything equivalent to the US gun show over in Britain. Also, if you havent checked it out, look at Dr. Rich Stein's site, helluva nice guy.
THE JAPANESE SWORD INDEX There's alot of good info there. Anyways, if youre real cheap, but want something more traditional looking than an HI Kat, and have some spare time, you could alwas buy a bare blade from Kris Cutlery, and mount it up yourself. Not quite traditional, but a decent price, and a fun weekend project.