The best goose call between $0-$40 is..................the one that you can blow and make sound like a goose. You're gonna get all kinds of replies from us and no two will be the same. You're best bet is to find somewhere you can try them out yourself, then you'll know what the best one is for you. I may love a call, but when you blow it, you might hate it. No two people blow a call the same, so it's up to you to find out what's best.
But since you asked, the calls I've blown in that price range that I've liked are the BG Canada Hammer II, Zink polys, Quackhead Goozilla.