The first time I was ripped off was my own damn fault.
I had bought some cheap weed from this guy I worked with, and had made plans to get about 2.5 oz from him one day. He showed up at the meeting spot (I rode my bike) and he was w/ a friend in his car. Told me to get in and leave the bike, said we'd be back in 30 seconds and no one would steal it. So I did, and we just drove around the block real quick. I tried to weigh it but he flipped out saying "PUT THAT DOWN SOMEONE'S GONNA SEE IT WHAT ARE YOU DOING!!??" so I didn't get the chance to check my scale, but I'd never bought more than a 1/4 oz and the bag looked huge.
Later that night I was supposed to sell 1 and 1/2 oz of the 2 1/2 oz to my friend who fronted me the money. It turned out I had only bought 1 1/2 oz and I never got my money back, lost about $100. He quit that job I worked with him soon after. I actually bought from him one more time in a pinch though. I hated myself for it too.
Bought what I think was fake opium tar. The first time I got really really high off it, but it got stolen. Twice I bought more about a year later, and I think those 2 times it was fake. It didn't do anything for me. Tasted/smelled like flowers, and was all gooey and sticky. But I'm pretty sure it was fake, though I have no idea what it could have really been.
I hate people who sell fake shit. They should all never be allowed to do real drugs again. Plus people they ripped off should recieve compensation plus interest for their troubles.
Oh and for these above reasons, I no longer do anything that requires buying from a shady person/"friend"/etc etc. No more pot (had always been my favorite but the guy who sold me the fake opium was my pot hookup). No more e, no more ghb, I'm stuck sticking to alcohol and poppy tea (which isn't bad, but not exactly cost effective).