I think this has happened before, but the GSP shipping to the USA has just gone wild. Seems to be affecting all my listings (though iits not easy to check - i was alerted by US buyer)
The cost to send a print in a tube is £1,500 on one of my items
contacted ebay but to be honest it does not appear to be being treated with any urgency,. They said I would hear back in 5-7 days!!
They also said I could send outside the GSP if its cheaper BUT with the new payment rules (for private sellers) I dont get paid until its delivered in the USA if I send direct
I just dont think ebay cares about it's small sellers any more
