A turbo express is fun to have if say you want to play them on the go or out game hunting and want to test the games first.
If you do want to buy one theres somethings you should know, a Turbo Express is not cheap and most of them have sound issues as they age. It's a simple fix (just replace a sound transistor from what I understand) But it's an extra cost.
Good luck hunting T16 games, I have 72 games for my T16 and 22 for T16CD and most are not cheap. I had to trade close to $200 worth of extra games I had to get Bonk 3.
I personally like to use my Turbo Duo when playing my T16 games and lately been getting more PC Engine Imports. (T16 in Japan in case someone doesn't know)