Don't rule out the older monitors, I picked up a IBM 21 inch monitor on ebay for $60.00, shipping was about $20.00, using ups. The cable was a 13w??, I can't remember but it cost $15.00.
So for under $100.00 I now have a 21 inch monitor that can run 1600x1200 at 72 mhz. I usually run it at 1280x1024 at 85 mhz.
If you chose this route, be careful, some of those older monitors have something called fixed resolution, which you then have to use a special video card, or work around it, but it sounds pretty complicated.