Long before the SNES came out here, there were some non-heated conversions at school about Genesis having better looking games than TurboGrafx-16 but that NEC's console had the better playing games.
But by the time school was getting ready to let out for the summer, the heavier hitting Sega advertising against Nintendo and larger software lineup no doubt had the side effect of crushing NEC's mindshare, not to mention its market share which would be next to nothing in the U.S. by the time Sonic came out in mid 1991.
The prices of TurboGrafx-16 games were awfully high. The best example of that was R-Type. At Toys R US it went for $69.99.
It's not like Sega didn't have expensive games either. Phantasy Star II retailed for $79.99 (6 'Mega Memory' plus a 110 page hint book in March 1990) but that was more understandable for such a large game plus the extra hint book in color, plus a map, not counting the instruction manual.
Even after I got a TG-16 a year after Genesis, I still saw R-Type in TRU for $69.99. Mind you, this was before the era of "BOMBA, price cuts", GameStop pre-owned games, and HD games costing an extra $10 over the standard $49.99 that started with the 360 / PS3 gen.