As of now only my headphone amp uses 12ax7. I would buy a pair I they were reasonably priced. If they really want to sell volume to the guitar community they have to be $80 -$100 …. Or less.
I have a few friends that play and I have retubed their amps and they thought $30 each was pushing it. JJ tubes at $20 - $ 35 depending on type are reasonable in my opinion and some sound great, like the gold pin 12ax7 and the ecc803s . Great sounding tubes. That’s what came stock in my Zesto Leto pre and that thing sounded amazing