In general, the higher positions for an AdWords ad is more expensive than those below it. But if that same group of ads appears on the second SERP, would the advertisers be charged the same rate as if it was displayed on the first SERP? Less? As this question relates to AdSense, do the same rates apply for those ads on each Publisher's web pages displaying them?
I'mnot quite sure of your argument, but Im pretty sure that when displayed in google SERPS, they would attract the same cost regadless if a user clicked on them from viewing the first or subsequent pages of SERPS.
As far as Adsense is concerned, nobody knows what an advertiser is pays per click except for Google (and the advertiser in aggregated terms), and whether this changes depending on the page clicked on from an Adsense site. Adsense sites cannot be SERPS anyway, each page is treated as a different page of content with different terms relevant to it.
again, Im not quite sure what you are getting it and what the "windfall" for publishers could possibly be?