Should have a little more info on the differences between the plans on the front page. For instance if you are going to say 150 submissions on the free plan - what are those on the other two?
Yes as swedal says, you need to tell what the other two packages include. But besides that it looks ok I think
Very nice site. I like the buttons and tabs. The only issue I'm having, is that it does not appear to be W3C compliant. The doctype seems to be wrong, so you might want to look into that. Overall, very well done.