My opinion on this issue is much different than most of the folks on this thread. I also think that some of the people that have voiced their opinion probably don't comprehend due to the weights they typically see.

I would be lying if I said I didn't short people ~5% of weight or overcharge when I buy midgrade/schwag. If I buy it for ~35/oz, I sell it for 50/oz, even to friends. Not because I don't like them, but because that is the market price, and anyone buying from me most likely can get it elsewhere. I do not overcharge but if there is money to be made on a transaction, I have no problems pocketing my buddy's 20.00 because I risk myself when i am holding, driving, walking with it.

If it is my personal stash (see sig) or some hi-quality, you get every last .x gram but if its a middleman situation, I will usually markup 5-20.00. I get 'rid' of my personal stash for free OR market price, not because I want to make money, but because thats how you get into trouble with other people who may "compete" with you (and you may not even know it).

One could argue that the 'market price' is whatever the buyer is willing to pay for it.

Lets say someone came up to me and said "hey, can I get a quarter from you?" and I say "im a little light right now, but if you are willing to do 120.00 for the 1/4, we could talk."

Now if you think thats a dick move, reanalyze the situation. If you are not willing to buy for 120, thats totally cool with me. I'll smoke the 1/4 and you can go dry or find another 1/4. Good luck.