1:18 scale aircraft

Hi im new to modeling and was hoping someone could steer me in the right direction, I am very interested in the 1:18 scale aircraft pre built by 21 century and Blue box, I have purchased the Japanese Zero and the P 51 Donald duck, very pleased with the detail on both, im looking for the F-16 and F-18 having seen some on e bay , the price is not bad, but the guy wants 40 dollars for shipping kind of high I am thinking, if anyone knows of a place I can purchase these aircraft with a decent shipping price please let me know, I have heard that they are coming out with a F-4 Viet Nam model and a B-25 in 1:18 scale can not wait to order, having worked on F-4s during the war and after at the Depot level iam looking forward to getting one, anyone's help would be nice, thank you for readiing and take care