After having played CM for some time I feel that it is best not to buy your own units. Let the AI buy for you and see what happens, it is more fun and the going can get very tough! Damn no tanks and that tiger is over defending that hill. That way you have to use sound tatctics to win and you will learn in to process. Wich helps you when you fight human oponents.
And Icelanders are the best soldiers..... I bet you didn't know that.