Alright, well the seller agreed to sell me quantity 3, so I no longer have any need to do this GB. Sorry for anyone who might have been interested!
The seller on ebay is a new account with no history that sells a ton of random toys and crap, then a couple heatsinks. My guess is they're drop-shipping from an alibaba seller. I'll bet if you check out the store number in the image they use, you could buy direct:
Anyway, the ebay seller is 2018vipkid, and here's the listing: https://www.ebay.ca/itm/162980838252
I was able to get qty 3, 190mm x 80mm heatsinks, anodized black, for $17.70USD each.
And with that, I'm closing this thread.