I agree it's high. I sold a very nice HQ-180AC for around $200 at a swap
meet a couple of years ago. Of course, swap meets are full of chronic
cheapskates :-)

That receiver is new enough that it doesn't use a bunch of old paper
capacitors, so there is not much to check apart from what has already been
mentioned.

I enjoyed my 180, although the audio quality is nothing to write home about.
Receivers with push-pull audio are more to my taste.

If it has a matching Hammarlund speaker, that adds to the value. Those may
sell for $50 to as much as $100 if the right person wants one. They are much
more scarce than the radios themselves, since some purchasers used a
different speaker or headphones. I regret selling my speaker for as little
as I did.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html