I'v got friends on both ends of the spectrum. When I was working and making good money, I would smoke my two boys out and sell to them super cheap. Mostly bud but harder shit too. My bad friend has a small little bowl (an actual bowl, not a pipe) with a lid, about the size of a half dollar. It was a running joke that he would always open it and look for bud the magically appeared. I would occasionally sneak a gram or 2 in and he would find it in the middle of a session, and id tell him to save it for later, this blunts on me. When this dude started selling weed he wouldn't front me a dime or even give me a fair deal, selling grams of mids for $15-20 a piece. I'm sure its mostly because he fronts all his weed and burns it before he can break even, but thats no excuse to do a good friend like he does.
My "good" boy on the other hand, the dude I first started getting high with is pure awesomeness. I shared allot with him that my other boy wouldn't even do, coke, downers,etc. He's always good on fronts, and its almost become a rule that we share our stash if the other is (not)high and dry. Two days ago he gave me 60mg of hydrocodone and a good chunk of bud, and said "remember when you hooked me up all the time?"
They're rare in the drug culture but you can find good friends.