An interesting thread which I haven't read before. I am one of those people remote from stamp clubs and from stamp dealers. When I restarted my collecting it was initially with Snail Mail auctions. A few times, when a trip to Vancouver coincided with an auction there, I was able to attend a sale and I continue to believe that the experience of a live auction is one of the most entertaining things that a person can do.
The discovery of
ebay about 10 years back was a wonder as far as finding material and I have had very few problems over the years, including the random bouts of selling done in the last little while. I do not recall any true nasty experiences at all and the only somewhat acrimonious back and forth I have ever had was with an mail auction.
I have found that
ebay is becoming less user friendly with mountains of "Bargain" listings to avoid and more restrictions imposed on both Buyer and Seller so I am finding that my purchases are becoming more restricted to a few tried and true dealers. They, by the way, are usually very open to Bank Money Orders which save the fees PayPal charges and which happen to be free (for me) through a very old chequing account with all sorts of grandfathered features that my bank absolutely hates but hasn't yet figured out how to deny. Canadian dealers often accept cheques as well though that is completely useless for cross border transactions.
And trying the Canadian
ebay site (or GB, or ..) might be worthwhile. I know I have sent a small lot (letter size) to Cuba recently and their payment was Paypal though whether through a friend in the States or not I don't know.