so a couple hundred bucks gets you a used Art Pro Vla or an RNC or a used RNLA. $300-$400 gets you a new Pro Vla or a new RNLA I think (which might be the only option if you can't find used in your craigslist or ebay if you're into ebay).
those are the three modern ones that are very good, as good as plugs with the advantages of being hardware (you can track with them and catch things before they get to your converters, you get knobs, dials, real meters). but of course plugs are cheaper and much more convenient, and some plugs that emulate high end comps will give you specific things you can't get from these relatively inexpensive hardware models.
used there are lots more options but also lots of crap so it's hard to list them all. tons of makes that are really good, more makes yet that just suck, and some makes have great and terrible units both (like art with the levelar that sucks and the pro vla that is awesome).
by the way a used behringer composer (like my composer pro mdx 2200) is like $60 and are really good clean comps similar to the rnc (not as good but not far off) and very versatile. there are lots of caveats and things you need to know if you own one, like don't use the single knob limiter at all, if you need to limit set the compression level to limiting (infinity or 20:1 or whatever high level reduction you think you want). also in general don't compress too much, you'll hear artifacts that you won't at lower compression levels. and with composers only run them in a fully balanced line. if they run unbalanced they sound like ass. if you don't know what that means or plan on using your board's inserts (which are unbalanced in all single-cable insert jack interfaces/boards), don't buy one. if you use an outboard mic pre with balanced output, into composer pro with balanced cable, out of composer pro into balanced input on interface or mixer with balanced cable, you'll get very very good sound. composers are vastly superior to most 3630s while costing less on the used market. rev 3630 being an exception, but still a different sound (a little darker than composer's transparency).
I'm not kidding here, I have some nice compressors too. the berry's are my cheap way of getting transparent compression for the time being (until more cash starts coming in again). nothing wrong with them if you use them well and follow those rules.
cheers,
Don
