And yet he stays in Corinth for some time, and continues to write to all his assemblies, to visit them, and to send his fellow travelers to them.
Keep in mind, he could have said "Oh, yes, indeed, that's a great idea", collected his installment, then vanished. But instead he refuses money and continues to perform manual labor.
The thing is, so far I've seen no "scam theory" here at all.
Nobody has yet articulated any coherent or plausible theory describing what Paul's alleged scam is or how he's pulling it off and, most importantly -- especially if the collection for the poor is the scam -- why he spends so little time on that and so much time on completely unrelated matters.
So far it's just "sounds fishy to me", but that's not a coherent, complete, plausible, evidence-based hypothesis.
As far as I can see, there simply is no "scam" theory to be rebutted.
I guess this is as good a time as any to bring up Eisenman again. He has a theory about Paul as, not so much a "Scam Artist", but more an "Agent Provocateur".
From what I understand (I could be wrong about this, his arguments get pretty obscure), Eisenman makes a link between the "Damascus" where Paul was going on orders from the High Priest, to root out followers of "The Way", with the Qumran Community.
The Damascus Document:
http://en.wikipedia.org/wiki/Damascus_Document
...
The fragments found by Solomon Schechter in the Ben Ezra Synagogue were original called the Zadokite Fragments, but after the work was found at Qumran, the name was changed because the document has numerous references to Damascus.[1] The way this Damascus is treated in the document makes it possible that it was not a literal reference to Damascus in Syria, but to be understood either geographically for Babylon or Qumran itself. If symbolic, it is probably taking up the Biblical language found in Amos 5:27, "therefore I shall take you into exile beyond Damascus"; Damascus was part of Israel under King David, and the Damascus Document expresses an eschatalogical hope of the restoration of a Davidic monarchy
Here's a translation of the scroll:
http://www.loc.gov/exhibits/scrolls/scr4.html#damasc
If we accept this possibility that Paul wasn't being sent hundreds of miles away to Syria, but rather to the large encampment of religious fanatics who claimed to be "The True Israel" making a "Straight path for The Lord" in the wilderness just a few miles down the road from Jerusalem - Then it really doesn't seem too far-fetched.
Paul says he spent three years in Damascus. What's that about? Well, if he wanted to infiltrate the religious community at Qumran and get to know the ring-leaders, he would need to stay "undercover" for several years:
...
Of the examination of initiants.
When a man enters the covenant, minded to act in accordance with all the foregoing ordinances and formally to ally himself to the holy congregation, inquiry is to be made concerning his temper in human relations and his understanding and performance in matters of doctrine. This inquiry is to be conducted jointly by the priests who have undertaken concertedly to uphold God's Covenant and to supervise the execution of all the ordinances which He has commanded, and by a majority of the laity who have likewise undertaken concertedly to return to that Covenant. Every many is then to be registered in a particular rank, one after the other, by the standard of his attitudes and their performance are to be reviewed, however, year by year, some being then promoted by virtue of their (improved) understanding and the integrity of their conduct, and others demoted for their waywardness.
http://www.essene.com/History&Essenes/md.htm
So now this theory has Paul as an undercover agent of the Jewish Authorities weaseling his way into this religious community. If we can believe what it says in the "Manual of Discipline", this community numbered in the thousands. If the population of Jerusalem at the time is 20,000 and there was 2000 people in this community, that's 10%. What chance does one lone agent have against thousands of fanatics? He obviously can't fight them or just arrest them and haul them in for questioning...
So he sews discord. The old, "get them fighting amongst themselves" trick. What if this network of Evangelists and other Churches that Paul glommed onto were off-shoots of this Qumran "Way". They are part of this gang waiting for the Messiah when Paul shows up obviously credentialed (he spent three years at Damascus) and starts preaching about his Jesus as Messiah schtick.
I think Eisenman's theory is that Jesus had been one of the leaders of the Community and that his brother James took over after his death. They believed in strict adherence to The Law of Moses and would have been shocked and outraged by the blasphemy of calling a man "The Son Of God". Paul deliberately chose a Greek religious trope that would appeal to the Hellenised members of the group and outrage the Hebrews. (which might also explain why he said he had to flee Damascus for his life when he started preaching about Jesus)
If his mission was to prevent these people from instigating a revolt against Rome, he failed. If his intention was to create a new religion combining Greek and Hebrew theologies, I'd say he succeeded.
That is a very brief and incomplete outline of what I understand of Eisenman. I'm not advocating this as "It must have happened this way", just - "I don't think it's impossible". And as this thread has demonstrated, "I don't think it's impossible" seems to be about as much as anyone can hope for in the Historical Jesus game.