I can tell you a bit about the AXA and EXA test notes, since I discovered the AXA's. The community where I lived at the time was one of the target communities where test notes were sent (they weren't distributed everywhere). I spotted a bundle of nice unc AXA's in the teller's cash where I did my banking, and bought ten of them. I sent one to Lub Wojtiw, editor of the Canadian Prefix Newsletter at the time, who eventually figured out what the note was - all I knew was that it was different and obviously special. I sold some of them off to other collectors, dollar for dollar, and the few I had left over I sold years later by auction, at a nice profit. We also received the EXA's a short time later, but I didn't track down a source for uncs, and just gathered a few nicer ones out of circulation. There was no thought among collectors at the time that these notes would become rather high priced in a few years, they were just something interesting to comment on, save a few, and spend the rest.