I know it is a break from the $100 budget but a 4k (3840x2160) monitor is almost a necessity for me right now. I have two Seiki 39" each of which has replaced four 21" monitors.
If you like larger copy on your workstations 50" may work really well it equates to roughly four 25" monitors in a two by two setup.
I found the 50" version a little too large for my purposes I have my monitor wall mounted about 3ft in front of my face and 50" would create the Wimbledon effect.
Yes, I know, not $100. Sorry for breaking the rules. I don't know any "good" $100 monitors.