mulmaster

Hey Does anyone know why walmart.com and toyrus.com aren't selling these things (i.e. alternators, not binaltech)? Both sites only have the alternator smokescreen and sideswipe available for sale, but nothing else (i.e. hound, silverstreak, deadend, tracks, etc.), which I believe are available in the US. The reason I ask is because I prefer not to pay $50.00 when I can pay less then half for a slightly inferior version. Any assistance/info would be greatly appreciated. Thanks. Mully