Thanks a lot for the info.I would have said $5-$10 at a yard sale. It's not something someone is going to come searching for, it's something someone will have to see and say, "That's cheap, I think I'll take that."
But after looking more into it, it seems to be an iconic piece. Released in 1998, it was one of the first flat panel displays.
The cheapest one on eBay is selling for $115 + $40 shipping. https://www.ebay.com/itm/SGI-1600-SW-flat-panel-display-with-micro-touch-overlay-installed-no-stand/272624731964?epid=2017427111&hash=item3f79b3473c:g:ltQAAOSwTM5Y6l8p&LH_BIN=1