I had a similar problem trying to buy some fonts today. I've made several orders successfully over the last couple of weeks, and didn't knowingly do anything different this time, but now I checkout through Paypal, it takes me to Paypal and I login there, it takes me back to the Saberfont page to finally confirm the order and I get an error: "There is no shipping option for the address you entered. Please go back and check the address."
It won't let me finish the order whatever I do to the addresses (even though these shouldn't be needed anyway they are all filled out).
Anyone else having problems?
Update - I've made a couple of orders for individual fonts since this with no problem - but different ones than I had the problem with. Either it's a random issue, or it's font dependent. I raised an issue on the site and got a reply so hopefully it will be tracked down.