Ok, I think you may be a little confused with how the site works.
The "more you pay the more designs you see" thing means, more people will enter the contest if the prize is bigger.
You don't HAVE to pick any designer, which is what worries me, because basically you can get a bunch of images, pick and choose ideas you like, and then have an inhouse designer combine those ideas for hourly rate. It's like a free way to give your company designer a starting point. O_o
As a consumer asking for designs, it's perfect... You don't have to pick anything, you can get a good idea of what you like and then take the concept to a designer. It's like saying "Here, steal my work"
I'm sure a lot of people find designs they love and they pay for them and all is well. However, I'm sure that many more just use the site for getting a bunch of thumbnail concepts.