Wow...the info on his website is really misleading then. I agree with you and can fully relate to what you are saying. There are many people who claim expertise in my field without the education, experience, etc. and that does not make me happy. TC
Northwestern University may at one time have offered specialized degrees in sub-fields, but that paradigm may have ended over the years. Therefore, even though there might be no current university that offers a BA or BS in numismatics, it does not necessarily mean that at one time there couldn't have been such a degree offered. That is just a long winded way of writing that any claim of a BA or BS in numismatics from Northwestern University may be truthful. Please also note that I am in no way attacking the knowledge base of Kagin. He has an exceptional amount of experience in the field and knows a tremendous amount about his niche while likely knowing quite a bit about other numismatic areas, too. My point in this thread is the PhD claim if it was granted from a non-accredited university.
I guess this depends a bit upon personal preference and the field that one works within. In my field (the sciences) it is commonplace to refer to others as "Dr. ..." and it is also common and accepted that business cards, papers or memos will start with "Dr. ..." and/or end with "PhD". This is not viewed as conceited, but rather viewed as a way of recognizing those with specialized knowledge, study, competancy and contribution to a field of study. Very few folks I have met in my field have ever demanded to be addressed as "Dr." in verbal communications. In fact, only one person I have encountered has demanded that title in verbal communication. Instead, folks go by their first names.
And that is exactly how Kagin and Jonathan Kern earned their degrees in Numismatics. By self directed course programs approved by their advisory committees.