I won't pay over $10 for any eBook and usually not over $5 unless it's an author I already know I like, so would normally skip a series like this. However, with %100 rebate it's a little more attractive, as I know the micropay will eventually be used up on buying < $10 books that I'd have bought anyway.
Hopefully the rebates will crop up on the other book I wouldn't mind reading but refuse to pay more than $10 for.
Still, I guess it's a good thing, otherwise I'd spend way too much on books and never find time to read them all, struggling as it is