Here's a very good question

[byndbored]

How much would be needed to added to a 64 bit game in order for it to be worth $60? (if it was made today)

[super_chris85]

Well it depends on the quality of the game already because there are games that are 64-bit that already sell for $25

[Chishio Kunrin]

People today are pretty spoiled by fancy graphics eyecandy, to be honest.

I'm sad to admit that I have even fallen victim to it. I would rather buy the HD collection of DMC than buy the original versions of the first three games. Why? I'm not sure I want to backtrack to the old graphics, when there are HD versions available.
In short - I'd rather spend $25 on the HD collection than spend probably less than that on the original versions because of better graphics.
*Ashamed*