Anyone know Ebay's policy on changing the shipping method?

DoNotInsertIntoMouth · 2013-10-23T19:18:23.000Z

I sell most of my stuff with free shipping depending on my price points, etc. I discuss this in my shipping article, but being on the East Coast, shipping prices vary greatly as you go west. USPS gets ridiculous where FEDEX stays pretty low. But close, USPS is way better. So I usually put USPS on all my listings. But every once in a while I will ship FEDEX if its either cheaper or faster (I never choose cheaper if it will get there slower). I recently had a buyer get bent out of shape about this even though he got his item the same day he would have anyway. So does anyone know Ebay's policy? Should I offer two free shipping methods so I am covered (if that works) and it will say USPS or FEDEX? It is already in my description in the listings that I may ship FEDEX.