What's the deal with Canary and why have these amps been FS for so long?

I was the under the impression that Canary was an excellent boutique brand.
I've also been considering 300b amps for some time now. 
These Canary 300b amps seem like they aren't grossly over priced, yet they have been FS for 2 and 3 years each according to my hifishark searching. 

As I'm looking for a tube amp in this wattage range, should I be considering these?

I guess I'm just surprised they have been FS for so long.

fs 3 years

fs 2 years
I had the. CA306 stereo amp and loved it, also had the Pass Labs XA30.5 at the same time and it was spooky how much these amps had in common as far as If you liked one you would like the other. When I put the 306 up for sale I had to run it twice with only 1 injury before the sale. With that said,  the amp was really nice and well worth the investment, but buy low cause you are going to sell low. Enjoy the music
Canary makes very well built and good sounding gear but for some reason they don’t get much attention. 
I've owned lots of amps ss and tube. I have the Canary M350's with 300b and 6sn7 tubes. You can't go wrong with these mono blocks. Running a pair of Legacy Whispers (without the built in amps. Also ran Wilson Witt series II, and Lipinski L707''s. Cary Slp 98 Pre. Excellent sound with every combination.