If you had a dozen pairs of classic vintage ubes in your closet

I'm using those very same S&H tubes in my Manley Steelhead.  And this will killya:  They were given to me by a friend who converted to solid state.  Don't ask me if I like them, because I am biased to love them, now that you told me how much they could be worth.

You wrote, "Perhaps you are biased in your listening, I'm not, very engineer based analytical."  What about this exchange of ideas would support that idea? It's a scientific fact that we as humans harbor subconscious biases that affect what we see and hear, no matter how hard we may try to be neutral or "analytical". Spending big bucks on a tube would tend to enforce a very conscious bias in favor of that tube. This is why science that reports human behavior or relies upon it always has to include enough subjects to ameliorate the bias effect and preferably be conducted in a blinded or double-blinded fashion.  I am sure you know this, and that is all I was trying to say.  You could be analytical as a single observer, if you are making measurements with a reliable instrument.  But since this is all about opinions, there is no avoiding bias.

You do realize that all tubes are aging during every minute that you are using them, do you not? So, you can pay hundreds or thousands of dollars for tubes that may sound wonderful on day one. That is a best case scenario, because in many cases inexpensive tubes will sound better than these rare NOS tubes that cost a great deal of money. But let’s assume that The expensive tube does sound great. From that moment forward it is decaying. Eventually your investment will fizzle out. You can get much more bang for the buck, if you learn how to solder, and how to read a schematic, and upgrade coupling capacitors for example in your gear. That sort of change is permanent and never goes away. Capacitors make a far larger difference to overall sound quality than do tubes.

Furthermore, when you do pay big bucks for a tube and install it, you are then very biased toward hearing an improvement. None of us is free from that listener bias. You have spent the money, so it must’ve done a lot of good. Get your wife or someone who doesn’t know what you did to have a listen, before you get wild over a boutique vacuum tube.

Most often, these days, the vendor himself did not own the tube from "new", meaning he did not buy it from one of the old time businesses like Radio Shack or Heathkit that once had brick and mortar stores and sold truly new tubes over the counter.   So the seller only knows that the tube looks new and has a proper box to go with it.  That is why I would value sellers that have their own high quality test equipment and are willing to warrant that a tube tests within new specifications.  There are a few out there.  But how did this get into a discussion of fraud in the tube business?  I thought we were talking about the impulse to tube roll.

Are you talking about tubes as investments or tubes as electronic devices that are needed for music amplification?

As one who has been doing this for more than 45 years, I disagree that a tube tester is a requirement. Second, I especially disagree that a cheap tube tester is a requirement. If a tube has an internal short, you will know it immediately without testing it formally. You will throw that tube away. If the tube is wearing such that it affects sound quality, your ears will tell you that. If you have a voltmeter, you can test a tube in the chassis by measuring its associated voltages. A really good and therefore expensive tube tester is nice to own, because it gives you something to play with. However, even the common expensive tube testers cannot test a tube at the voltages and currents that usually exist in functioning equipment. Therefore, you would get a false impression of the performance of the tube in circuit. For most of us, it is best to just Use your ears. To acquire a tube tester that can actually test tubes under real world conditions will cost you well over $1000, more like $2000.

Are you asking why people don't replace worn out tubes? Or are you asking why people don't feel compelled to audition tubes they own, even when the tubes in use are fine?