Purchasing barely used NAD gear

Thanks guys.  Recapping is not something I have the skills to do.  Would the law of a diminishing return come into play here?  If it's spendy,  I don't see the point.  I'm not a rich guy LoL

Well, that is pretty inexpensive. NAD gear was great for the money. I actually have given my integrated amp to a friend of mine that is 35 years old and it bested his inexpensive contemporary stuff… not recapped. 
 

Honestly at that price, as long as it works and sounds good to you, sounds like a bargain to me.

Time - cost - quality - risk. 

nad is notoriously unreliable, although the 80s stuff you list is much less finicky than their later gear and also sounds good. the amp and preamp seem to go for $200-$220 each on ebay and the tuner for $50-60; depending on condition and whether you save on shipping $575 for the set seems like a fair (but not great) deal.