It's interesting to reflect on this number, when you realize that the latest AAA platform title (whatever AAA meant in that particular day/age) have always cost about $50-60 in the past $$ terms of that day, regards of when in the past 20 years we're talking about. So you paid $90 worth of value in 1990 and we pay $49.99 today. What I mean to say is that games were EXPENSIVE back then!
A big difference then was that you could expect to reliably sell your used game back after you finished playing it, if you didn't want to hang on to it. So if you were into playing a lot of games and only keeping your all time favorites, you could reduce that cost significantly. And at the same time, if you were willing to wait a little bit after a launch, you could have the game for a nice discount. How often are you able to sell a game you pay $60 for today? And it doesn't help that the same game is repackaged and sold 10 times over a few years by the same company, each time for $60. At best that's a DLC, maybe worth $10 or $15, not another $60. :|
But market forces were very different too. You would expect thousands of sales, not millions, and your development team was a dozen people, not five hundred.
Development got harder (more art assets to make, harder code to write, more of everything) markets got bigger (100 million Wiis vs 50 million NES's) and demographics shifted (from 8 - 16 year olds to 16 - 30 year olds).
I think you still have rose tinted glasses. I still remember paying about AU$80 for Sonic The Hedgehog 2 on the Sega Master System, and about AU$90 for Sonic 3 on the Mega Drive.
In real terms, games are cheaper here too.
(Another reason for lower prices would also be lower unit costs -- a ROM cartridge surely cost more to manufacture than an optical disc. And the gaming audience is now much larger than it used to be.)
I remember early 80's cartridges for Atari 2600 in the Sears catalogs being $80-120 USD a lot of the time. Though I don't think I ever paid more than about $40 myself.. I remember being REALLY disappointed in a few.. and miss a few today.
To me, the preview video for the game looks like Star Wars meets Half Life.
Wolfram Alpha says[1] that's ~$90 today.
1: http://www.wolframalpha.com/input/?i=50%20USD%201990%20in%20...