The EBS Multicomp is within your price range, and I love it for bass. It's a stompbox style compressor that's transparent and excellent at what it's intended to do. Simple design, two knobs and a 3 way toggle. While the available controls may appear overly simplistic on the surface, less is more when it comes to available settings for bass compression in my opinion.
I typically set the compression between 9 and 12 o'clock which provides all the compression you'll ever need for pick or fingerstyle. You'll notice the onset of 'squash' associated with overcompression around 3 o'clock or so, however such a setting might be appropriate for slap style. Typically you wouldn't adjust the comp ratio past 2 o'clock though. Take the box in and out via the stomp switch while adjusting the gain until your post-compression level is spot on with your pre-compression signal and you're good to go.
There's also a 3 position toggle switch which I prefer set to TubeSim as it adds a pleasant dash of warmth to the signal. From there I run the signal to my RBI pre for recording, or my SVP pre for live situations. This is the ONLY box I'll put in line before my preamp, and believe me, I've tried a bunch. Alternatively, I'm sure this box would run fine in the f/x loop too. While I'm sure many sub $200 compressors add a tad of noise to a signal, I don't detect an appreciable amount from the EBS.
While I love most of Tech 21's stuff, I would avoid
the Bass Compactor due to that unit being too noisy. If they could clean it up, it imparts a cool sound and all, it's just too noisy.