To be honest, I never have purchased multiple items using the GSP for this very reason - however, your seller does seem a bit disappointed that the GSP isn't all it's cracked up to be, and therefore might be open to combining and shipping outside the GSP, if you did in fact ask. I have been using the GSP a fair bit lately, but primarily because I've bought a couple of large lots, which actually seemed to be cheaper using it, and obviously I'm not combining shipping. What I am peeved about, is the fact that every time I use it, it refuses delivery to my PO box, and I have to use my house address which annoys me no end.