Here is equipment catalog of DEC. Mean prices is very approximate. It depends on seller: ebay, USA, England, Russia
equipment catalog
monitors / vt200 family
Model, P/N Item Mean price ~
VS240 CONTROLLER FOR VR240 OR VR241 149 $
VS240-A CONTROLLER FOR VR240 OR VR241 149 $
VS240-B CONTROLLER FOR VR240 OR VR241 149 $
VS240-C CONTROLLER FOR VR240 OR VR241 149 $
VT220 GENERAL 199 $
VT220-A2 WHITE 199 $
VT220-B2 GREEN 199 $
VT220-C2 AMBER 199 $
VT220-D2 WHITE 199 $
VT220-D3 VT220 terminal 500 $
VT220-E2 GREEN 199 $
VT220-F2 AMBER 199 $
VT240 VS240-X W/VR201 MONO 449 $
VT240-A2 VS240-X W/VR201 MONO 449 $
VT241 VS240-B W/VR241 COLOR MONITOR -
VT278 DECMATE W/KYBD 499 $