No no no, the FMR compresser isn't $400, and it's not one channel! It's the PRE-AMP (the RNP) that sells for over $400. The RNC, on the other hand, is a stereo compressor that sells brand new for about $170-$175, shipped and everything! But if you might have use for a gate/expander, or any other features found on the Behringer models, they're worth looking into.
And if you like the Behringer compressors, it's also worth looking into the older models that are being blown out right now. You can get a brand new Autocom Pro for $70, or a Composer Pro for $90. And if you don't mind an "open box" item, or even a used one, they can be had for like $50. Check out
www.zzounds.com/a--2676837 and
www.samedaymusic.com. They have a number available, but probably not for long. I see that the used and opened Autocom Pros are already gone, but they have some Composer Pros for $70! It's a lot better than paying the $110 for the new Composer Pro XL! You don't get the tube emulator, but everyone says it sucks anyway, so who cares!
That said though, there ARE a number of different features in these different Behringers, so it's worth looking at what you think you'll need the most. If you're mainly going to be using it for guitar/bass stuff, you don't need the de-esser, which is the main addition to the Composer Pro XL, along with the tube emulator. You could just get the Composer Pro, so that you have the better gate/limiter (as compared to the Autocom Pro), and not waste your money on a unit that only adds useless things like the enhancer, the de-esser, and the tooby thingy.