These boards can be good or bad. The build quality is great, and they are sweet to use as long as the switches stay clean. If they get gritty and nasty at some point, they are no good. I got a new one with a Dell set in the late-90s and used it for years. It is still good and my son is using it today.
The black ones do not age well, appearance-wise. I have had beige ones that were yellowed, but mostly they hold their looks pretty well.
I have bought and sold several on ebay, they usually trade in the $15-25 range plus shipping. Black ones are much harder to find.
Expect to buy 2-3 before you get a nice one, or wait patiently for a NIB.