I have one of the DOS card 6100 models (there is printing on the 6100 case so you know). Its fun to mess around with and since it has built in sound you can play games. Like anything else collectable if a glut hit the market they would be worthless, but in a dry spell somebody will pay a few bucks for one (if it has the correct cable). The downside is you are kind of stuck with a limited OS you can use (same with the Apple PCI Pentium cards for the 75xx and 85xx series) plus you need the correct cable. 486 and Pentium 1 cards are limited in what you can do. I prefer Nubus  cards from OrangePC since its cool running OS 7.x and Win 3 on the same machine.