The other day I purchased a TG-16 game locally to use as a test cartridge on the TurboDuo. Looking on eBay I had an impulse buy for another TG-16 game.
Final Lap Twin (C - $7)
Galaga '90 (C - $18 shipped)
I'm leaning towards not caring about boxes and just getting jewel case + manual and cartridge/CD for Turbo games.