Those who have been posting musings about how eBay Canada should get its own international forwarding service like the US eBay International Shipping or the UK Global Shipping Programme should consider that, for right now at least, the UK GSP has shut out US buyers from purchasing from listings where the program is being used. This is after it was noted earlier this week that the UK GSP was suddenly displaying even higher than usual charges for buyers.
This is one thread I found on the .com board on the subject, but I'm sure there are others:
https://community.ebay.com/t5/Shipping/Can-t-buy-from-UK-sellers-anymore/m-p/35077491
