Postage prices did go up recently in America, so for the seller to be covered by Paypal/Ebay in a dispute, they have to use a certain type of postage... which is now about 50% more than before.
Sellers can still use a cheaper shipping method, but if you claim that it didn't arrive, the seller can't prove to ebay that it was sent.
It's a shame too, as most of the good stuff is in America, but now shipping makes it impossible to buy individual or small items.
Best thing is to find someone with several items you want, and get a shipping quote for the combined lot.... or have someone over there that you can trust to buy and forward items to you. (or go to a convention over there and just splurge)
The American sellers won't care too much if they don't get any foreign buyers from the high postage costs, as most don't bother (or want) opening it up to non-Americans to begin with.