I think that the subject of "price" can be taken in two ways.
1) Should all games be 60$
2) how do you price a game which isnt as encompassing as say, Mass Effect (which is a 40+ hour adventure)
Its hard to justify minor changes to an existing platform and still charge full price, I think we can all agree on that. The issue then becomes, how much "change" warrants a full $$ pricetag.
For example, lets look at CoD MW3, a game which a lot of people (at least when you look at reviews of it) feel was just a copy paste of MW2.
MW3, has a "refined" graphics engine, which they have been using over the last couple of games. To some, heavy graphical upgrades make for a significant change to a game. MW3 suffers from game spanning issues, such as poor hit detection, poor spawn locations/spawn logic, and fairly poor connectivity (course I Could be biased as I want dedicated servers). Fixing these issues could be considered a significant change to the game.
I think that games which pump out yearly updates are the games which would suffer the most from the "why am I paying full price for this" syndrome, because...well lets be honest.. its every 3-4 games that something drastically different is done.