Depends on the card. I have found a good collection of assorted capacitors, a host of surface mount components, on some useable fans and heat sinks. Some are worth removing components from and some are junk. The same is true for audio and other PC cards as well as old motherboards.
i dont find it worth it to desolder SM capacitors and resistors since theyre cheap anyway
one time i removed a nice DC fan from a boombox that i was throwing out...i almost felt like the fan was worth as much as what i would get if i tried to sell the boombox
i would say thru-hole resistors would be worth removing and keeping though