You will get more and more entries as you get closer to the end of the contest time period. Some designers like to enter contests early on. Some designers don't enter a contest until has four days left. Some only enter in the last day. It just depends on the individual's strategy. With a prize like that, you'll get entries, I'm sure. You might want to use the Not Interested category as sparingly as possible, rank as many as you have time for, give as much direction as possible, both in the general comment section and on the individual designers' pages. Honestly, though, I'm sure you'll get plenty of interest as time goes on.
Hope that helps a little,
Laura