Great, so the three games I actually really want (Exile 2, Vasteel, and Ys 3) are all outside of my price range.
Heck, the reason I got interested in TG16 stuff in the first place was because I found out back in the late 90's that Working Designs released some games for it.
I understand your price frustrations - we're all frustrated - but I don't understand your surprise or "woe is me!" attitude. Are you phishing for pity sales? It's hard to believe you haven't searched for these games on ebay before or read the dubious "rare and valuable" guide on Racketboy. It's 2012 and everyone knows retro prices are outrageous. It's a terrible time to dive into good underdog consoles. That's why I don't play Sega CD or Saturn - they look awesome and I'd love to have the Working Designs games, but I know I missed the boat and I don't feel like spending thousands of dollars. If you're on a budget, go check out 3DO, 32X, or Master System. None of this should come as a surprise to you.
On the bright side, this isn't an entirely bad time to discover the Turbo scene:
1) many PCE games continue to fall in price. Games like Dracula X and Rainbow Islands sell for half of what they once did.
2) the most advanced homebrew just came out.
3) forum raffles and freebies are out of control.
4) there's never been a better time to repair your console or buy aftermarket goods (hucard sleeves, power supplies, inserts, manuals, etc.)
5) over one-third of the U.S. library is available on the Virtual Console.
6) flash cards are better than ever.
Going back to your want list, there are four copies of Ys III immediately available on mainstream websites for $45-56. Wait for an auction or forum sale and you'll find it even cheaper. The going rate for Exile 2 is unfortunate, but, like Tron said, the difficulty is messed up. Take comfort in the fact that the first one is the better game and buy the PCE version of the sequel which literally only costs $10. WD's Vasteel was a $30-50 game for YEARS and is a very recent addition to the $100+ club. Be patient and you might yet find a reasonable price.
What are some of the good US CD and Super CD games that wont cost me $50+?
The good news is that we've already mentioned every $100+ CD and SCD in this thread. I'm pretty sure any CD we haven't mentioned can be found for <$50.