Can excellent tubes transcend modest amps?


I am wondering how far a good but not amazing amp design with decent parts such as Antique Sound Lab AQ1003 DT or a Jolida 302B can be improved by putting top notch NOS tubes? In other words, is it worth buying a used $500 integrated and give it an extreme tube make over for $200-400 rather than buying say a PrimaLuna or Cayin in the $800-900 range with its stock tubes?
kanuk
The price difference of most tube amplifiers has more to do with power supply, voltage regulation and output transformer quality than what type of tubes they use. Tube rolling is basically a tweak; so I doubt you're going to turn a $200 amp into a $1000 amp with just tubes. Also remember that amps made in China are much cheaper than elsewhere so the quality comparison shouldn't be readily assumed by a labor rate differential.
My first comment was that the better and more resolving the system, the more the qualities of NOS tubes would be appreciated. NO- They WON'T transform junk, and I fully agree that a well built power supply, quality caps, etc. ARE an absolute must for "high end" reproduction, but: Quality NOS tubes will still take a mediocre amp to higher level, and the differences will not be subtle. Incidently: A high-dollar set of Michelins WILL have more traction, and result in better stability, ride comfort and handling on ANY given car(providing said car didn't already have a better set of tires on it). Will they transform an Impala into a C6? Of course not! They WILL however make an improvement.
So a Cayin 70 0r 88 with a bit of tube upgrade may be the best of both world in the budget category?