Pioneer home system value

As others have stated, it is dependent upon the electronic, mechanical, and cosmetic condition of each piece.  The receiver is the star of the package.  If the CAPS have been replaced and the pots cleaned, recent sales have been $1500 to $2500 as listed on HiFiShark.  The speakers and turn table about $1000 each.  If they have not been serviced or in poor condition, I cannot guess on market vslue value.  Try contacting Reverb, Skylabs Audio Shop, or Vintage Audio Exchange if you want to consign or sell them outright to these establishments.  Remember, you will only realize 70% to 75% of final sale price but you do not have the hassle of marketing or dealing with the public.  

@mark7660 These were outstanding pieces when they were available in the late seventies. Pioneer was at the top of it’s game and this system would have received much critical and public acclaim. As others have mentioned in this thread the equipment is approaching 50 years old and if you have the acquaintance of a qualified technician with insight into these components I would seek their guidance on how to proceed.

One more thing, the prices people are asking for similar equipment on the internet is not synonymous with value but rather with what a seller thinks or hopes people will pay!

Oh, if you drop one of these components model numbers into your browser's search bar, you'll find a zillion of them out there someone's trying to sell I bet many saying "original owner" when they've never even heard a hifi or spun a record or CD in their lives. Beware!

The reason the vintage gear is still desired is because it looks a lot more attractive than most contemporary gear.  I'd just try to buy the Receiver and Turntable, because those will continue to go up in value. The speakers should be a throw in because unless the speakers are rare, they're not going to be worth investing money unless they sounds pretty good already

As to capping receivers from 50 year old gear.  As someone who has recapped several receivers of that era, it is rare for the caps to be bad and probably more receivers have been ruined by unnecessary capping than made better.  

You say you know the owner, go listen to it.  Marantz, Pioneer, and Sansui are really solidly built but may need a bit of TLC when it comes to the pots and selectors.   I recently replaced the output transistors for a friend with a Marantz 2285.  Really easy to work on and the feel of the weighted tuning wheel for FM and the overall quality of it were bargains for the build quality.

The only reason to buy this is nostalgia.  As others have noted current gear, even budget end, will do a much greater job at music reproduction.  And even if the owner has really done a great job maintaining it magnets and capacitors cannot be reasonably expected to be in top shape after half a century