Competitive exhibitions for paintings and the like run pretty much the same way; it's how it is! And cliveh is right, some such events are a bit shifty. I have stuck to smaller local shows which have smaller prizes and presumably less attention and marketing, but hey, it's a hobby. Many such events are put on by non-profit organizations to raise funds, and as such usually ask commissions of 30% or so on sales too. A local Audubon Society site has been having a juried art and photography show for a number of years now.

I like to characterize the whole thing as playing the lottery -- but you have to bring a picture or two.