A very interesting thread and a heck of a study of human nature in a small dedicated community. I personally focused on one issue a bit different from all the issues and opinions mentioned. and that is I am surprised how ignorant the 'middle man" is of how very very close he came to committing fraud. If the contents of that box are not as expected, it is Fraud, and his own emails detail the actions nicely. There is only one description I can think of for the actions to date, and that is stupidity.
You know what? If something goes south, I will buy the damn books just to bring it to a conclusion, and I will pay the darn lost time/shipping you are out of pocket, and if it doesn't go south and the books come back as expected, I will still buy them, in case you can't sell them. I am not a collector, but learn a lot from this forum, and if it comes to pass, I will donate the damn things to Dr. X, for use in his annual thingamajig, and I will do it just to spite this middle man.
If the package is not correct as to contents, etc. I would not hesitate to notify the USPS Fraud unit.
As to outing the fellow, that is up to the community. I don't care either way, because it is not like he/she remains anonymous. The middle man left so many clues and so many people already know, and the tracking number itself reveals a lot and it would be public access information, that this middle man is a dingbat. Now imaging his/her employer getting this thread. Jesus. risking all this for $675? Dumazz.
Let me know if you want the #, and where to send.