I am in this same boat. I bought a brand new Corvette in high school, my first house at 19. All with money from picking up broken TVs in the trash and at garage sales, fixing and selling them in the paper and doing repairs on older TVs that the shops thought were too old. I was a kid, so most TV owners wouldn't trust me with a new $1000 Sony 26", but there were a heck of a lot of PortaColors and old round tube TVs in my neighborhood in West Los Angeles that I would get repair jobs on. On used sales, I got $100-$250 for any color console, $200 for most portable colors, and $35-$50 for B&W sets. And I could get them for between nothing and maybe $50 for a nonworking late-model set. On repairs, I usually charged $45 + parts on B&W and $75+ parts on color console, and $100+ parts on Sony and solid state flat. This was from the late 70s to the mid 80s, I call the Golden Days of Used TV.
Rented mobile home? You JCFitz are not alone! Just moved into mine in June... New Corvette is now a 10-year-old Toyota Diesel pickup. I actually don't even repair TVs anymore, as I got tired of being called a crook when I wanted $50 to fix TVs that could be bought new for $99 even though it was maybe a 2-hour troubleshoot plus parts. And the only used TVs that I can make good money on (after having fun fixing

) are the round tube color sets for collectors and other antique sets. I just threw out a nice RCA 20" late 90s table model that was working fine. Nobody wanted it, and I put it at the dumpster with a sign FREE, WORKS! It was still there when the trash truck came for it.
WalMart is one cause, along with the manufacturers who enslave 9-year-old children in the Far East and Africa to assemble the new TVs and other electronics for a bowl of rice. And we buy it all. Shame on us, I suppose. We cooked our own goose. It was better before. Yes; you could buy a 12" B&W TV at Zody's or Gemco in the early 70s cheap, but for the livingroom TV you would go (in Los Angeles) to Ham the Zenith Man or Harvey's. The properly paid salesman would find the right TV for you, and would personally deliver it and install it that night. And the shop that sold it to you would work to build a relationship from which you would call them back for service, and even buy a second TV from them for the bedroom. Times gone by but fondly remembered.
I hope John R. Meagher (author, Pict-O-Guide, and RCA head tech and maybe most famous pioneering TV repairman) was able to escape (retire) in time before this career disappeared... Bless him, I think he probably did
Charles