Well, Magical Chase was $100 about 10 years ago. Games like Dungeon Explorer II and Godzilla were aways worth MSRP or more. Things started to get really stupid...not that long ago, really. Maybe 4-5 years ago? They got hella stupid just in the last two years.
While its a bad time to just start on TG-16, there has never been a better time for PC Engine. What the more frugal minded people do is buy all PC Engine stuff except for the dozen or so US games that have a lot text in them. There is zero point whatsoever in having a censored, case-less, US Bonk 3 HuCard for four times the price of a JP one, but you will always want a US version of Ys 1&2, Y's III, Neutopia 1 and 2, Dungeon Explorer 1 and 2, Cosmic Fantasy 2, Dragon Slayer...I'm forgetting a few here. It Came From the Desert...not much else. Most (all?) of the US exclusives, Darkwing Duck, Madden, can just be skipped totally. A US Ninja Spirit is (was?) cheaper than the JP version a lot of the times, so you might want a US version of that too.
All the shooters, the platformers, China Warrior, etc, just get JP versions. A large number of the best games didn't come out in the US at all. Ys IV, half the shooters, the entire Arcade Card library, and virtually all of the fighters, are JP only.