I’m building a vinyl system up from scratch. I’ve been researching vintage integrated amp’s such as the Pioneer SX and Marantz 22xx series and using AK as a resource for reviews and market values. My question is have the sold values of these amps gone up in the last 5 years are so?
OK--others have provided the basic "economics" of the market regarding the models that you have on your "wish list". I'll throw another angle at you, that you should seriously consider.
Are you really looking for a "vinyl system" or a "vintage system"? The two are distinctly different, and not "mutually exclusive" or "mandatory". You can choose either/or/both in setting up your system to meet your price and performance needs.
You have referenced only receivers. Do you really want/need a tuner? If not, an integrated amp will work just fine. If you do, an integrated amp will still do just fine, since the prices of even high-quality tuners is way down due to the slow and painful death of radio, and you can grab one for a few bucks. If it is just "the look" of that big illuminated dial and pointer, then you are just going have to be prepared to pay for the aesthetics, rather than useful performance.
Not knocking vintage gear (pretty much everything I own falls into that category, other than modern digital interfaces), but there is modern gear out there (with "classic" styling), that can meet or exceed the performance of "vintage" gear, without the need for service or full restoration $$$, and often including additional features (like a remote or built-in DAC)--and a warranty card.
You already still have your vintage TT, so a quick going-over, and you are good-to-go in that dept.
Lastly--do you really recall, or have recently listened to the vintage gear that you referenced in your original inquiry? "Sonic memory" is not always as good as one would like to believe, and the "memories of days gone by" walking through those aisles and rooms full of big silver-faced receivers (that we drooled over, but couldn't afford) can often cloud our judgement when re-entering "the hobby". Take a good hard (objective) look at your vinyl collection, and all those "gems" you refer to, and then look to see how many titles fall into the category of "what the f**k was I thinking when I bought that one?", and you'll know what I mean.
Sorry for the long read, but I believe these are important considerations.
Good luck with your journey!!!