If it's the only option you have they could just raise the price without implementing 3D. After all, ticket prices have risen over time for the same formats. Of course, the reality is that you always at the bare minimum have the option to just not go to the cinema.
No not quite. The thing is that they have a normal mix of 2D and 3D showings but not on the release day. So the issue is of wanting to see it the first day. So they have the normal division of prices between the two of them, but you are essentially forced to go for the more expensive one if you want to see it when it is released.