Best Value in Used Bryston Amps and Monoblocks

As a long time fan of Magnepan's, I have always wanted to try Bryston amps, especially their monoblocks which are rumoured to be a very good match for my speakers, and have also been recommended by Magneplanar over the years, albeit off the record.

What I can't figure out, however, is the logic to the Bryston product line, where there is value in the used market, or which version or vintage I might buy for a reasonable price.

I can't tell which ones are monoblocks vs single chassis stereo amps, I don't care about "THX" designations or multi channel and I don't know what "SST" means.

From time to time, I will see a SINGLE monoblock for sale, which I keep in mind for my next mono system, or perhaps when I want a mismatched, high powered center channel.

I find weird ads which supposedly have brand new, never opened, but 5 years old "NOS" (new old stock) which I suppose were obtained through a time machine or recovered from a sunken ship in perfect shape.

Then I find ads for what look like basically new ones, which are suprisingly expensive, or battle scarred old amps with faceplates so scratched they look like they were traded in a drug deal and ended up in a pawn shop.

I read good things about Bryston's customer service, but every time I have reached out to them to try and better understand this, I get more than a whiff of we really don't care if you buy our products or not attitude, despite the fact that there is no dealer in my area.

So in summary, can someone please explain the history of these amps, which ones sound best, and what vintage might represent the best value in today's market?

I don't have a set budget, but thinking I would sell my Levinson 23.5 for $2-2500, so < $3K would be great.

Thank you,

cwlondon