I agree with Scaredgirl, that people should be able to pick some preferred elements, but nothing more than that, just as a signal to the masters.
Because is we do Icy's system, we could end up with
45 people preferring earth, meaning earth can pick the one they want, and bid even one less that the other elements, giving the other elements a hudge disadvantage.
And as most people will prefer the same elements, the other elements will be left with less cards, meaning they will have less cards, or noob players, which means they have a greater change to lose the war, so people don't want to fight for them in the next war etc.
I also think you should be able to pick a less preferred element (only one), but also only as a signal to the masters.