For sale is my 27"/29" Makvision M3129DF-TS arcade monitor.
It's working and in great shape. These tri-sync monitors are rare now, and if you are building a MAME arcade, these are ideal. This model auto switches resolutions, no switches to move when switching from standard, medium, or high resolution games. It has an 15-pin dsub input (VGA) I will provide a VGA/CGA adapter if you wanna hook up a board without a VGA input cable.
Pics are when attached to my raspberry pi (@240p) to show working as of Oct 30th.
Price is $315.