Thwarting spam - it's not rocket science
Still, I will read it - the economic approach seems more promising than the legal.
"wealth transfer from senders to recipients" -- that sounds like "money". From what I hear, it's an old Heinlein idea; applied to telephone calls, in some book of his.
Any economic approach to reducing spam, will need a technical infrastructure. If this one involves money, it is too complex to be feasible.