Yup thats very true, I was just saying yesterday i'm not actually sure why I buy the limited / collectors editions of games.
I always have done for the Gears of War and Halo, I think because there my favorite game series and i originally wanted the extra content such as the bonus DVD's and so on.
Must admit I have always managed to get the limited edition cheaper than the normal edition of the game, with the exception of Gears 3, although i did save £15 on the limited edition so i dont feel too bad about it.
For any other games I just go for the cheapest possible copy.