Hello.
Biggest one for cheap is NEC MultiSync or Eizo Flexscan. Both have 21" or 21,3" in 4:3 or 5:4. 1600x1200 Pixel and an IPS Panel for a wide viewing Angle.
I`ve bought them for about 75,- € each. They have very good Quality because, they were made for Graphical work.
Sorry, for my English.