Last time I bought tubes from Upscale Audio the salesman asked what "level" of tube did I prefer: 1. Good Matched 2. Excellent Matched 3. Kevin’s stash or 4. the best ones that are then cryogenically treated? What’s the cost is my question and the cryo tubes were close to double the price. I went for door #3.
Interestingly, I asked him if the cryo tubes sounded much different, he replied that no they sound the same "But some audio guys just have to have all kinds of stuff cryo’d so we offer it as a service."
I just shock my head.
Regards,
barts