Advice: Royalties/Proceeds?

[vellacraptor.livejournal.com]

A friend, whom we will call K, recently wanted to hire me for a comic book. I told him if he gives me a portion of the profits, I'd sell it for 8$ per page, and if not then I'd sell it for 20$ per page. The pages are pre-layed out (though I'd probably have to do tweaking), and it'd only be inks. From what I understand I'd be fairly simple and around 28 pages. I figured since I wasn't getting the profits or anything after except my name on it if it went big, 20$ was a fair price considering most people charge 50$ per page at the low end of the pool.

He thought it was too expensive, said he could find someone cheaper, then after researching found what I told him about 50$ per page to be true. Still, since he'd be playing publisher, he wanted to try and get a cheaper price.

So my question is (considering he'd be selling the comics at around 2$ per book I believe) how much of the profits should I request? I think 10-20% of the profits is the average, but he's charging so low, I'm afraid I'll hardly get anything? Should I just stick to my higher price and not have to worry about calculating every book sold? Also, if I do decide to do the percentages, how long should it last?

Thanks!

UPDATE: We talked about it more...apparently he'd be taking the comic to comic con and selling it there, which would get lots of sales easily, and also selling it to a distributer. HOWEVER, with your advice and the fact that even with my limited knowledge I can tell K has no clue with what he's doing (and recent-past has made him somewhat on the bitter level as a friend, and showed his dislike/limited to no knowledge for legalities/professionalism), I am steering way clear of this project.

Thank you guys for all the help!