Definitely provide a cleaner PM conversation. Trying to read the original PM conversation was - well - kind of a lesson in madness.
I read that whole PM exchange top to bottom. My takeaway was this:
--Miamiknight and Action page seller negotiate a payment date, what books MK would send as trade, and who would cover what shipping
--Seller says something to the effect of, "People told me you are getting a a great deal so you should cover shipping"
--MK says, alrighty, then I will sweeten the deal on my end to make it more equitable
--Seller replies, "Nonsense, nonsense, more nonsense about not being allowed to trade books, you're getting too good of a deal, I'm calling off the sale."
There's the possibility that someone PMed the seller with a better offer. The seller did state he was getting a bunch of PMs telling him he was selling low on the page.