Love the idea; we'll definitely give it some thought, especially how the experts can profit from these fees well after they post the flight option.
Aside: we really didn't expect this post to get to the top of HN. Our intern was running around the apartment saying, "I told you we should have planned better."
When a post is on top of HN, I don't think we're used to seeing the meat of the content stuck behind a quasi-paywall.
EDIT: It looks like you've posted the results publicly now, nice.