especially for those individuals new to tube equipment and their understandable desire to upgrade by way of the universally held "holy grail" vintage tubes. I read a fine column by George Gruhn in Vintage Guitar magazine back in the mid 2000's (right before the crash in 2008) that dealt specifically with Fender guitars and the ease of producing of high grade counterfeits by way of their construction and the vast amounts of monies involved in the vintage market. at the time it was nothing to see standard finish Tele's and Strats going for $50,000, $60,000 and more- and low production run custom colors higher still. Mr. Gruhn laid it out in all it's ugly reality- and the advice was pretty straight forward. if you were not truly equipped to spot a fake, or did not have access to an expert so equipped then you had best have seriously deep pockets and be prepared to take a potential hit of enormous proportions. I have been reading extensively on this same scenario when dealing with the Vintage/NOS vacuum tube market and frankly I have finished some of the articles with my sphincter wound up like a snare drum. the levels of deception are mind blowing- from remarking tubes (in many cases so well that again an individual would need to be equipped to the same level as museum procurators dealing with antiquities to spot the fakes) as well as the aging/production of boxes/packaging that to an inexperienced person looks absolutely genuine. and all driven by the ever escalating prices as the finite supply of authentic tubes grows ever smaller in relation to demand. at the risk of repeating previously referenced material the Hall of Shame by Vacuum Tubes Inc. in particular is a Must Read for anyone venturing into this market place. a serious read of this, and similar articles, will give one a whole new perspective when sifting through the numerous offerings through Ebay in particular. it is of critical importance to utilize the experience of seasoned players/techs in choosing reputable dealers who value the reputations they have earned through honest and ethical business practices and are proactive in rooting out the bad players, as well as those who are either no better equipped to spot the fakes or simply do not care. I apologize for the length of this post. but even with over 50years of playing tube equipment I was Totally unprepared for, and shocked by the level of deception in this area. there are many solid, reputable dealers out there- but there are also Untold numbers who, whether intentionally or through their own shortcomings, are Not. you work hard for your money, and you are genuinely motivated to get the best out of your equipment. take care that in the process you don't become another victim to this growing problem.