A few years ago I gutted and rebuilt the Heathkit AA-32 tube integrated amp I assembled in 1968. Cost of the rebuild was somewhere around $340. When new, the kit was $70 CAD - 8WPC.
Four NOS 6GW8 output tubes were $130 CAD and the price quoted in the assembly manual was $1.25. Two of the originals had gone red plate so I thought to replace all of them.
It's neat to have it in running condition but can't say tube amps are worth the expense. Depite that, I wound up with an AGS Trio receiver that cost maybe $12 but not a single tube inside as I dscovered after purchasing - one of those MaxSold offerings.
It weighs a ton and concensus is 12 to 15 WPC. Got four new Sovtek 6BQ5's from Jim McShane for it's ouputs and did (nearly) an entire recap. All the other tubes were obtained "here & there".
I'm well over $200 into it and it's still a work in progress. During the recap process, one channel on Phono was lost. Probably knocked out when poking inside the rats nest of wires while doing the re-cap. Not a priority now but will do more investigateing....sometime.
I don't find the dollars per watt ratio for tube gear to be particularly attractive. Being involved with audio gear as a job for as long as I was, presented opportinities to hear a good bit of tube gear. But I have to confess, it elicited yawns on my part. And a headshake or two at the expense some will undertake to own a tube rig.
But if I had unlimited funds, I could see myself seriously considering a couple of those mamoth mono tube Carver amps. They look awsome.