@orpheus10
Any NOS tube from military bunch made by Telefunken or Mullard in the 50s or 60s are exclussive nowadays, but you pay more for the brand. Japanese tubes are no so expensive, as far as i know British Mullard made Matsushita tube factory in Japan. Those japanese tubes are really amazing and highly competitive to the best British made Mullard, but for less $
Although NOS tubes are expensive, I would never purchase any that were even more expensive as a result of "exclusivity".
Any NOS tube from military bunch made by Telefunken or Mullard in the 50s or 60s are exclussive nowadays, but you pay more for the brand. Japanese tubes are no so expensive, as far as i know British Mullard made Matsushita tube factory in Japan. Those japanese tubes are really amazing and highly competitive to the best British made Mullard, but for less $