The "old stuff" that I look for at hamfests is more like capacitors, coils, inductors, transformers, meters, dials, wirewound and carbon composition resistors, coil clips, plate and grid cap metal spring clips, tube sockets, vintage microphones, etc., and only items I know I don't already have but could use, or specific elusive items I have been seeking for decades. The only fully-built transmitters and receivers I would even think twice about are the extremely rare or unusual, for example a high quality 1920s or 30s homebrew transmitter in excellent condition that I would actually use on the air; I don't even glance at the DX-100s, Viking IIs, or even R-390 series (unless maybe if in exceptional condition and price). Things I would have jumped onto 20 years ago, why would I bring home another, if I already have two copies? Storage space in getting to be a premium for me, and the stuff I keep an eye out for is getting sparser ever year. I would probably grab a $100 75A-4 in good shape with all the filters. I'm afraid you are right. Most of the vintage stuff has already been recycled through two or more previous owners, and the people who take an interest in it , if they themselves haven't gone SK, are now reaching the age where the previous owners were beginning to lighten their load. There are hardly any new enthusiasts for this kind of "stuff" coming on the scene behind us to take our place. Decades ago I only dreamt of owning a 75A-4; now I have two working 75A-4s, and two more dead ones that I'm in the process of trying to bring back to life. I could see the day in not-too-distant future when a working one in pristine condition wouldn't even fetch $100 at an event like Dayton. Nobody was interested in the rough-shape-but-restorable 75A-1 I took to Dayton last year; not even any low-ball offers. A young ham with a brand-new interest in building a high power AM station but with no vintage parts, equipment on hand, or extensive knowledge of hollow-state technology would likely become discouraged very quickly if he tried to gather up components and build a homebrew tube-type AM kilowatt. The stuff may be out there, but hardly anyone knows who has it or where it is (until they learn too late that a previous owner's collection was hauled to the dump), and only those who have accumulated a collection of old handbooks and magazines would even have the means of learning that technology. Instead, he would probably go the route of building up a class-E rig with solid state pulse-width modulator. Or more likely, a plug 'n play plastic radio with AM mode, into a leen-yar. A handful of power MOSFETS would be a lot cheaper and more readily available than a set of working high power transmitting tubes... and a lot lighter in weight and more compact than a high power modulation transformer with reactor. Plus, he probably has limited living and work space for putting up a ham station with antennas. Nevertheless, there are still a few of us around to enjoy it while we can, and it's a shame to see high quality and top-of-the-line older stuff mindlessly trashed or destroyed.