Section 2--204. Formation in General. (1) A contract for sale of goods may be made in any manner sufficient to show agreement, including conduct by both parties which recognizes the existence of such a contract. (2) An agreement sufficient to constitute a contract for sale may be found even though the moment of its making is undetermined. (3) Even though one or more terms are left open a contract for sale does not fail for indefiniteness if the parties have intended to make a contract and there is a reasonably certain basis for giving an appropriate remedy.