KEE will definitely be there selling paint. There may be other companies there as well as Karnage, Draxxus, and Valken have all expressed interest in coming on board.
Each company will set their own prices. If you are able to arrange something ahead of time through your local store or field that has an account with KEE, you may be able to get a better price than what they are offering there. I think Kee usually priced their paint around $40-$50 depending on the grade, but I'm not exactly sure.
You can expect to see prices as the event gets a little closer. Hope that helps.