Hey Plate, I would think you know I am a collector, but I am always on the lookout for 50 watt bassmans or similar fender amps that are not of collectable quality. Like ones with the transformers changed or just over the years have had chassis drilled making them players amps. Nothing wrong with them at all and are better finds if you intend modding one.
I found one in a homemade headbox that someone had tried to make something else out of. Never did get it, but the chassis have loads of room and the transformers ready for a lot. I made a single channel amp out of it and made a tube overdrive and added a 808 tube screamer. I have it apart waiting for time to add a gibson tremolo, or at least that WAS my plan, but I forgot about the vibrato/tremolo in the Vox until Sluckey took the time to resurrect the thing. Now I am thinking it may get one of those.
What I am saying is I like to find amps I can modify without the amp gods frowning upon me. The Bassman is my second favorite. First is a Super Reverb, but it has been years since I have found one of those and I don't expect to since ebay.
Anyway, if an amp is working it is hard for it not to be worth more than $200. I found one the other day at a antique flea market. Still don't know what it is, but I do know what a smooth plate Telefunken is and it had 3 in it. I paid their asking price of $40 and it also had a Stancor OT on it. Like I said, I don't even know what it is, but some of those OT are bringing $400 now.