they may have taken advantage of your brother because 20 for a joint is insane. in america everyone i've ever bought off and everywhere i've ever bought weed, 20 dollars gets me a twenty which is usually about 2 g's or 1/8 which you know how much that is, and one instance where i bought 1/4 off a guy for like 25. a joint though, i've never bought a joint for more than 5 USD, and no ones ever wanted more for it.