There is no US version of After Burner, it was Japan only (the only TG16 Sega port to get released in the US was Space Harrier). Also, US Air Zonk is somewhat expensive, it's definitely one of the higher-priced US cards. Neutopia I and espeically II definitely can be pricey too. And China Warrior is kind of bad, in my opinion... cheap, but bad. It's so hard and frustrating...

Anyway, cheap games? Yeah, good luck. Expect to pay $10-$30 for TG16 games, and only very rarely under $10. Shooters are definitely the system's best genre; platformers are generally very simple, NES-style. Some are hard and frustrating too, just like NES games. Anyway, cheap(er) games... Alien Crush, Keith Courage, Bonk's Adventure, R-Type, Sidearms, J.J. and Jeff, Legendary Axe, Blazing Lazers, maybe Bomberman, Dungeon Explorer, Dragon Spirit, Cyber Core, Devil Crush, Victory Run...

Neutopia and Military Madness might cost a little more, but are worth getting. Neutopia II... between the price and the long passwords, unless you have a TGCD or TurboBooster Plus (and thus have decided to spend a lot of money on this system), and can use the system saves instead of passwords (Neutopia I supports that as well, but its passwords aren't as long so not having it isn't quite as much of a burden) it may or may not be worth it. Bonk 3 and Air Zonk are generally pretty expensive too, and Bomberman '93 can be somewhat I think.

Really though, with the TG16 if you start liking it you will not be able to avoid sinking into a money pit. First it's just the US system, sure, and get some of the cheaper card games... but can you really resist getting a CD system? So many of the system's better games are on CD! And if you're doing that, a Japanese PC Engine Duo-R or Duo-RX is the best kind to get... and then you need to get it modded for US cards too maybe, and get an Arcade Card, and import games because so many of the best games are imports... and the multitaps, controllers (get some 6-button controllers for the fighting games, 3-button controllers for games with really awkward control schemes that use Select or Run as a button such as Forgotten Worlds...), etc... it adds up. Sorry, unless you really do stick to just the US HuCards, TG16 collecting is not cheap, to say the least. And while there definitely are a bunch of good US HuCards, there are so many great import titles too, and the Turbo CD had such a great lineup of games in Japan...