As you may know, my Green Stuff is from GF9. They offer a far better price than GW. They’ve recently released a new product called Grey Stuff. I am not sure what the advantages are of Grey Stuff over Green Stuff, but I thought I’d at least link to it. And for those who didn’t know where I got my Green Stuff, now you do know.
They also have things like Plastic Tubes and Plasticard.