All games are not created equal, but they worth the same?

One of the things I don't understand and I personally would love to change is the pricing model of retail games. Retail games vary in a huge spectrum between low budget titles to extreme high budget blockbuster titles, yet...all the games retail for 60$. More importantly, the value attached to the titles vary wildly as well

Lets compare a game like Medal of honor: Warfighter to a game like GTA IV:

MOH is one of the poorly rated military FPS to come out this generation because of poor gameplay, lackluster visuals and mediocre voice acting. Not only that you can finish the game in under 4 hours. Not sure about the budget but I am sure it couldn't be a lot.

GTA IV, a game fueled by 100$+ million budget is chocked full of content, quality voice acting, open ended gameplay all compiled in a neat package which takes around 35 hours to finish.

As expected, Medal of Honor: Warfighter did not do well at all, however, I always wonder if the game had a better chance of surviving if it cost something like 30$? Suddenly, Warfighter doesn't seem that much of a bad deal at all.

Yet...both of these games retailed for 60$, which I think is absurd and insulting to games like GTA IV, Skyrim.

So, what is the story behind fixed 60$ games?

Finally, I wish with this coming generation of console, the pricing structure of games would not be a static 60$, but more flexible pricing approach which could range anywhere from 30$ to 60$.