Collector's edition: cheap plastic knock-off stuff and crappy rushed DLC content. Hardly anyone offers a discount on pre-order AAA games. I'd rather spend $5 more than waste a whole $50-60 on a sub-par game.
Some people have the income for cheap plastic stuff, don't dis 'em. GMG offers usually 25% off on AAA.
All I'm saying is, taking things to either extreme, of pre-ordering everything or pre-ordering nothing is seriously just stupid. If you are an adult, you should be able to do the research and decide on what level of risk you're willing to spend money to buy a game early. Live like that, and you'll almost never get screwed by a pre-order.