Here, I'm selling a samsung LD220, a 21.5-inch, 16:9, 1080p display which apart from the VGA port, can be connected to your pc, laptop, or Raspberry Pi with USB. Yes, you can connect the display to your USB port and have a main, second (or third) monitor, as easy as that. Perfect for RPi.
It has never been used, and it's in as new condition! I bought it specifically for the RPi but never got to use it as I had no time. I bought it for 220 pounds, but I'm asking for just 80 pounds (plus s/h expenses to wherever you are!)