I don't charge friends. I have them buy us dinner or something like that.
Since they are not DVC members, did you invite them to vacation with you? Are they the only good friends you have? If not, remember you are setting a precedent and if you do one good friend a great favor, the other better get the same great favor. Plus, someone else may be looking at you as being their good friend, but you may not feel the same towards them. Now you are in the situation of alienating some friends and rating how good your good friends really are. Just be consistent in whatever you decide.
Since they are not DVC members, did you invite them to vacation with you? Are they the only good friends you have? If not, remember you are setting a precedent and if you do one good friend a great favor, the other better get the same great favor. Plus, someone else may be looking at you as being their good friend, but you may not feel the same towards them. Now you are in the situation of alienating some friends and rating how good your good friends really are. Just be consistent in whatever you decide.
In general...
Extra close friends and family pay nothing. Extended family and good friends pay maintenance. More casual friends pay rental prices ($10/pt).
Here's a good one for you! My niece is getting married in September and they are going to DW for their honeymoon. So I offered them a free week's stay at a DVC resort as a present! they turned me down! My niece told me they would rather stay at Port Orleans. My wife and I both told her that the rooms would be nicer, but still no go! They don't have much money and I thought was a nice gesture! A free week at DVC or an expensive stay at Port Orleans! I don't get it!