The answer for me, is that I spend way too much time looking through ebay listings. Even large sizes can be found with enough time spent looking - those Roblees I posted are 11.5B.
I do the same and then I kick myself in the head for finding amazing shoes that fit me in Deadstock condition that can't buy because shipping kills any possible deal and then I will have to pay high taxes on Customs. Like this pair I didn't get to buy for that reason:
NOT MINE just showing the pictures. They got sold for peanuts, less than 50$.