To CGA or not, that is the question

[AtariMaster]

All, 

Should I invest in a NOS 25” CGA monitor before they go extinct?
 
There are a few NOS still available, some are CGA and some are tri-mode.
 
I want to run original PCBs, ArcadeSD and multi JAMMA PCBs and emulate with a MAME computer.
 
I have 2 great VGA CRTs that would work for the ArcadeSD and MAME but not for the original JAMMA PCBs.
 
Are CGA monitors really rare and if my goals change down the road do you think I could sell it for what I have in it ($400-700)? Would it be better to invest in a tri-mode and not waste time with a CGA only?
 
Thanks,
Andy