When I was working stork at a downtown Toronto porn shop we would pay people between $.25 and (very very rarely) $1.00 per mag. Usually a quarter.

If you have crazy shit like the Vanessa Williams Penthouse issue you can probably name your price.

Don't expect to make a killing selling them but at least you'll know other pervs are getting the chance to see the stuff.

One time when I was much younger my friends and I found a brown paper bag under a tree in a park. Inside was a stack of porn mags and a gun. So there is another option, leave them someplace public but obscured from view, with a weapon. You'll make some kids day.