hmmm, i don't remember R-type being that expensive... but who knows? I bought my TG-16 games in Northern NJ from Toys - r - us, Electronic Boutique, local mom-n-pop store (Video Dynasty! ... what a great name) ... and later via mail-order.
From what I can recall, the first wave (or two) of launch titles were discounted to $20-30 range within a year (mid-late 1990). Power golf, ordyne, tennis, alien crush, etc. soon became the "budget" titles.
TG-16 games were expensive, upon release, here's what I remember:
most HuCard games, upon release, were $40-50. the CD games, upon release, were $50-60.
JJ & Jeff (early 1990?) $40 + tax... I only remember because the EB cashier was distracted, talking to a co-worker, and handed me back my original $50 dollars instead of my change!
1990: Splatterhouse, Bloody Wolf, Motoroader = ~ $40
late 1990:Ys = $55-60 (for a LONG time, because it was popular, I guess, but Monster Lair was discounted to $40 range by this time...)
1989: I can't remember how much blazing lazers , china warrior, and vigilante were, even though those were the first games my brothers and I bought when the system launched.
probably 1990: $35... sinstron, cyber core
Overall, though, I really can't remember specifics. Even the stuff above is hazy. I have all my original boxes still, but not the shrinkwrapping (which would have had a price sticker, especially the big fat EB ones). EB always had odd prices like $41.99, $56.99, $37.99... whereas ToysRus would have $5 increments (29.99, 34.99, 39.99)... or so I recall...