I always have extra pot from my grows. And I'll be damned if I would just give it away. :P
Just because I could sculpt a wooden chair for next to nothing, or I discovered oil in my back yard doesn't mean I would give it away. I would certainly charge what I thought the product was worth. It's bartering, and people have been doing it for thousands of years. As far as growing goes, electricity, water, nutes, replacing bulbs & ballasts can get expensive over time. This taboo IMHO needs to be erradicated.

I'm not a commerical grower or anything, (though I always dreamed of getting rich quick, who doesn't) but it's definately not immoral or wrong (maybe illegal ) to sell pot, or even make a little extra on the side. Economics. Supply & Demand. It's why we are a successful civilized race. Capitalism at it's finest. (I know there are alot of anti-capitalists, if you are really against capitalism you should move to China, N. Korea or any of the new USSR breakaways...)