I first owned Bloody Wolf, which I bought used, for $6 or so, in the early-mid 90's. I bought it, since it was so cheap, and I knew I'd eventually buy a TG-16.
At the end of the TG-16's life, I already had an Atari 2600, 5200, NES, SNES, Sega Genesis, and a Gameboy I only used in waiting rooms and such. I had chances for a TG-16 before, but I went with the SNES and later genesis, first.
I purchased the TG-16 at Evans Distributors & Jewelers, in Maryland. Evan's was a catalog store, like BEST and Service Merchandise. I forget how much the TG-16 was. it was marked down pretty low, so I'd say, between $30-$50. I also bought 7-10 games, for $5 or so a piece, including RAIDEN.
Later on, I had trouble finding games, since most places had sold their stock, or it was picked through. Not much at TRU, Babbages, Software etc, Radio Shack, etc.
I called the 1-800-DUO-THIS number I saw in a game mag, they were happy to help, sent me catalogs, and I got most of my other stuff through TZD, off and on, until they closed.
I got my 2nd TG-16 deck, and 80-100 games, from a video store that was getting rid of stuff that wasn't renting.
I traded in that 2nd TG-16 deck to TZD, for a new Turbo Duo. I remember doing that near x-mas, and having to go to Radio shack for an RF Modulator, because the TV I wanted to play it on, lacked RCA jacks.
2006 or 2007 I bought a Duo-R from a Japanese seller, then shipped it out to some guy on this forum, I forgtet whom, and had it modified for S-video and a region switch.
2008 or so, I got a Turbo Express, from MindRec, that has screwy sound. I got it, not so much to play on, but just to have.
There was the group buy for the Turbo Everdrive in 2014, I got in on.
I no longer play the Duo machine, since I got the Duo-R modified.