Are Pass Labs amps probably the best ever you can buy ?

Not even close in my experience. 

Better value and better sounding than the Nakamichi PA7 [Pass designed] amp is the Usher R1.5 which is also a Nelson Pass design[a Threshold Stasis 200 copy].
The SIT 3 might be the best sounding of all the Nelson Pass designs but you would want to compare it with the Bakoon amplifiers which have a somewhat similar approach.The Bakoons are the best sounding  SS amps I have heard .Not quite Kondo Ongaku quality but getting there.

Is the Giant Killer Belles Virtuoso amp on the market yet ?..

I would say they are in the "team photo".  So yes, among the best.  Great resale, sound, and support.

Love my 250.8 and XP22.

i’m curious on pass resale. the last time i purchased a pass amp securing a pretty deep discount was not difficult( 25-30 %off). has that changed? if big discounting is occurring resale usually takes a hit. the unit was a 250.8 as i recall. no motive here. just curious. it ‘seems’ that pass is widely used by agoners as well as ps audio. is discounting a factor in these two brands having so many users? i’m guessing the sound quality is pretty good too.