In all honestly, the $1 for a trial sign-up stinks (and the $30 if they stay reeks of another program that I know you don't want to be associated with anymore)
I'd much rather do a 50/50 split on everything (and would take that option over this one if it was offered)
While I do understand what you're trying to do, I think that $5 or $10 for the trial (with $25 or $20 if they stay) would be a little bit better of an offer.
If you're worried about fraud & whatnot with the straight PPS option, just offer it to certain webmasters that you know to be honest or have proved themselves to you with the revshare program. Some people will bitch, but who cares! Odds are the people that bitch that they have to use the revshare option would be the ones you'd have to keep an eye on if they were PPS
I can't get homegrown to load right now (probably a router on my end) so I can't look & see what the surfers are charged & the options for membership, otherwise I might have other options to throw out there