One thing that is nice about tubes is that they can be very easily tested for quality control. Because of that used tubes are a very viable option. The market in used tubes is virtually unlimited.
Also, in my experience the price of tubes is distorted by collectors/hoarders. Certain tubes and brands are commanding very high prices when there are readily available alternatives at much lower costs. For example, Mullard or Telefunken 12ax7s compared to U.S. made "organ" grade equivalents.
One last point, the differences between high quality, properly functioning tubes is subtle, yet like most things audiophile related users describe the differences as huge and earth shattering.
Also, in my experience the price of tubes is distorted by collectors/hoarders. Certain tubes and brands are commanding very high prices when there are readily available alternatives at much lower costs. For example, Mullard or Telefunken 12ax7s compared to U.S. made "organ" grade equivalents.
One last point, the differences between high quality, properly functioning tubes is subtle, yet like most things audiophile related users describe the differences as huge and earth shattering.