One's ability to differentiate between good and bad bud/weed. Newb smokers often suffer from this affliction and get ripped off.
"Yo bro, lend me some money and I'll get you some dank green, I promise"
-"Nah dude, I don't trust your budgment."
"Shiiiiit, my budgment is better than yours! Last week you bought some schwag just cus some dude told you it was good shit!"