Okay I have a question. I don't know if I asked you this already but the project I am doing requires only a certain amount of nodes published. Like this: 

1 Large ad - 2 Medium ads - 3 Small ads - 30 small text based ads for a set amount of time 30 days. And when one spot becomes available, that spot could be purchased by a user. Or could tie in with a calendar type view so they could pick the dates their nodes/ads get published? 

Is there a way to do this? I'm slightly new to Drupal, and maybe someone could give me a pointer. Thanks.