By the way, you can find some of our material on authorship issues linked here.I've only read some brief portions of Ehrman's book. I'll make several points here based on what little I've read of the book and what Michael Licona and others have said about it.As Licona notes, somebody like Paul didn't need to be wealthy in order to have access to some of the resources of a wealthy person. Sometimes wealth is just one way of attaining things that can also be attained by other means. The apostles were perceived among Christians as something like an equivalent of the prophets of the Old Testament era. They were the messengers of a new revelation. That status wouldn't give the apostles much standing among non-Christians, so somebody like Peter would be seen as little more than a relatively uneducated fisherman among them. But Peter had a far higher status among Christians.One of my pastors recently mentioned, I think during a sermon, that he was looking for a particular book he wanted to read. Predictably, somebody from the congregation tracked down a copy and gave it to him shortly afterward. All my pastor needed to do was say that he was interested in reading the book, and the resources of the congregation were put to use to produce it for him. The early Christians would have been even more interested in providing resources for somebody of the status of an apostle.It's also worth considering what I've written before about the process by which Ignatius of Antioch probably composed his letters. See here. Just as Christians would bring items like food to prisoners they were visiting, they probably also brought the supplies needed for writing letters. I doubt that Ignatius' Roman guards provided the supplies, and I doubt that Ignatius carried the supplies with him on his way to martyrdom. The Christians who visited Ignatius would have had an interest in getting him to write letters, which they would then take back to the letters' recipients. It would be in their interest to not only bring along items to write with and write on, but also one or more individuals who could do the writing or help with it. Much the same could be said of the New Testament letters written in a prison setting.And in non-prison settings, the New Testament authors would often have been surrounded by other Christians. They traveled with other Christians, spoke before their congregations, etc. Think of how many people Paul mentions in Romans 16, 1 Corinthians 16, etc. He would have frequently been surrounded with people able and willing to assist him in composing documents.At the beginning of this post, I mentioned some of the material we've written on authorship issues. Some of the articles we've written are about hostile corroboration of New Testament authorship. I don't know whether Ehrman addresses that subject in his book. I doubt he discusses it much, if at all. Unfortunately, that line of evidence is often neglected by more conservative scholars as well. Keep that evidence in mind as you read Ehrman's book and interact with others about it. It's not enough for Ehrman to address the early external evidence from Christian sources. He has to address the early external evidence from non-Christian sources as well.
Here's something else to keep in mind. My understanding is that Ehrman sometimes makes reference to how little we know about ancient writing practices, how he hasn't yet come across evidence for a particular practice, etc. But the early Christians and non-Christians who were making judgments about New Testament authorship lived in the ancient world. They had access to a lot of information that's inaccessible to Ehrman. And they were aware of differences in vocabulary, writing style, etc. among the New Testament documents. Dionysius of Alexandria writes about the differences between Revelation and the other documents attributed to John. Jerome attributes the differences between 1 Peter and 2 Peter to Peter's use of a secretary. Etc. A minority of ancient sources agreed with Ehrman about a minority of the New Testament documents. They argued against some New Testament books on the basis of the sort of internal evidence Ehrman highlights. But I don't know of any ancient source who assigned nearly as much weight to such objections as Ehrman seems to. When somebody like Dionysius of Alexandria notes the internal differences between Revelation and the gospel of John, for example, he doesn't seem to consider it anything like an insurmountable problem. And the minority objections to a minority of the books eventually faded away in most of the Christian world. The early Christian and non-Christian sources were aware of the sort of objections Ehrman is raising on the basis of internal evidence. But they didn't think the objections had the significance Ehrman is suggesting. They lived in the ancient world, in many cases spoke and/or wrote in Greek, and sometimes composed documents themselves in that ancient setting. They didn't need to wait several centuries for the scholarship of somebody like Bart Ehrman. They were familiar with objections like his, but didn't think much of them.
Jason, thanks for this helpful post and follow-on comments.Thought you might also want to be aware that John Hobbins at Ancient Hebrew Poetry also commented on Erhman's book:http://ancienthebrewpoetry.typepad.com/ancient_hebrew_poetry/2011/03/bart-ehrman-is-a-reverse-fundamentalist-a-fisk-of-his-huffpo-op-ed.html