One of the best scopes for its value currently is the DS1054Z, its 50 Mhz,
so far can be hacked to 100 Mhz, 4 channel, serial buss decode, FFT,
around $ 400. Lots of info on the blog about this scope, has had a few
firmware revisions.
Dave has done reviews on it. And other low end scopes.
Regards, Dana.