By sounds of how much you know about weed itself (you didn't state a weight, strain, or even if YOU think it's really good shit, just that youre brother said it was) I'd say there is a very high chance your were ripped off or at least got taken advantage of, cuz that's what my sister did when I first started smoking, I'd buy a bag and it was pinched HEAVILY every damn time. And she also made me leave my bags at her house cuz I didn't want to get caught with stinking bud going home and it would be half gone by the time I got back up to her house the next day, I finally caught on and got really pissed at her one day cuz she basically smoked a whole eighth and left a bowl and expected me not to notice! Her excuse was that she was the one who started me smoking and she was the one who found the bud for me. Needless to say I found my own connects quickly, and bought my own pipe cuz that was another excuse for her to leech bud off me. Sorry had to vent there, my sister was and is a seriously selfish leech.
But ya get your own connects or at least find out how much youre getting.