I don't know the going rates for stuff these days, but I would say you got a great deal. Why?
Well, it's all about SOLID games + kool hardware + "not-so-common" bonus items...
(1) There are haters, but I like the TG-CD. Sure, you might be limited with ability to play some software, but you are just starting out. Get the cheap solid games you can play now. Worry about other things after you've played all the good stuff available to you.
(2) TurboExpress is fun. Period.
(3) Hardcase for TurboExpress is kool. Not-so-common. You will give it to me. I will give you $20. The soft case for jewel cases is neat, too. I'll take it off your hands.
(4) You have an INSTA-LIBRARY with great games...Legendary Axe, Splatterhouse, Bonk1 and Bonk2 and Valis III (the best in the series) are SOLID and desirable. If you are a shoot-em-up fan, Sidearms is a great little game.
BOTTOM LINE: You couldn't have asked for a better INSTA-ENTRY into the world of TG-16