Hmm..that's a tough one. My initial feeling is, if you're still on CRT you have to get a new monitor ASAP...but I doubt there's anything out there that's good below $200. Maybe a 24" BenQ...like http://shop.benq.us/ProductDetail.aspx?id=50 is near.
I would _not_ recommend getting anything smaller than 24" in widescreen format, though. The 'FullHD' format has too few pixels anyway; good width but 1080 is not very much space vertically after all. I have a 27" FullHD which is nice but the old 21" that has 1200dpi vertical is much better for many a use.
My buddy actually has a 42" LCD for his computer monitor, but that's a bit too much already IMO. But, you might find a used 32" TV for ~200, if you settle for a TV as a monitor...they can have quite a nice picture too after all, compared to CRT that is.
One option would be to find two similar 19" used TFT's and use them side by side, could probably get used ones easily under $100 apiece. Seems to me it's nigh impossible to even dump 4:3 monitors these days. I've given away two 19" TFT's since nobody would pay even a 20 for one. Those would give u plenty of desktop space for very little $$. I'm longing for a 3rd monitor...but I need a secondary adapter for that. It'd be way nice to have a separate monitor to keep FX racks on for instance, or channel settings etc...and my secondary is now too far @ reserved for vox recording basically. I've been thinking maybe a small, like a 19" widescreen, but set up sideways next to my main monitor for easy laying of windows in a tall pile.
Of course music gear is nice too...but...you should treat your eyes as well sometime!