Welcome to VK!
Honestly you don't need an expensive tester to evaluate which CRT's have usable life. I own both a BK 466 and Sencore 70 and I tend to favor the 466 for it's simplicity. Dare I suggest there's a cult following of what could be considered the blind leading the blind when it comes to which tester is best. In my opinion ebay is a very poor representation of the fair market value of obsolete electronic test gear. CRT testers were mass produced by the 10's of thousands for the TV servicing industry and it's likely today that many still end up on the scrap heap. I hope that's not being too negative.
