I don't think Heathkit is still around. They used to make some good, low priced hi-fi kit amps, preamps, etc and test equipment along with companies like Eico and Dtnakit.
As lonote says, there's not much of a market for them in the musical instrument field. Their old tube hi-fi gear is being collected though. That one looks to be solid state, but I may be wrong.
I used to use an Eico 60 watt tube power amp that had a tube preamp, a copy of the Bassman circuit, added. Also a similar 60 watt Dynakit. They were good bass amps for that time and sounded better than any Fender or Ampeg amps then. Sunn amps were basically Dybakit amps in the beginning.
I still have a pair of working 60 watt Dynakit MK III amps for home stereo. They sound very good.
I don't think you'll get much on a resale of that amp even if it's working, unfortunately. But it will make a good conversation piece. Open it up and take a look inside to see what sort of amp it is.