If you have it stated in your listing and/or in your policies that you ship Standard, but they want a faster method, the customer should pay the extra. I'm sure someone will shoot me down for the suggestion, but why should you 'eat' that kind of cost?
The customer could be convo'ed before you ship, that higher cost/faster shipping to their destination costs $ more, and that you can cancel their order, put the item in RESERVE for them WITH THE HIGHER SHIPPING COST in the shipping info. (not meaning to 'shout', but don't attach the new shipping cost to the selling price or you get whacked for fees)
I have sold items that ended up being sent FedEx (which is NOT my norm) and the customer pays for the speed if they really have to have it right now.