Extremely late to the party - didn't know a single soul who had a TG-16 when I was growing up (this coming from someone who had a Sega Master System and managed to find 2 other kids in his neighborhood who also had SMS's), and EB Games / Babbages never had them on display. Christ, I didn't even play one until MGC 2011. Bought a SuperGrafx at that show and the rest is history.
I knew all about Turbo from reading magazines, of course. I do remember my local Toys r' Us and EB Games selling the boxed Turbo Duo + bonus pack on clearance for about $29.99 during the end of its lifespan, along with a slew of games like Vasteel, Exile: WP, etc in the bargain bin for $5. Hindsight...blah blah blah