Sometimes too many people think they are real friends with me, A few weeks back I did an album design for "friends" and soon they have their release party, but some days back he said to me that I maybe wont get in for free, because their guest performances also get in for free, and they are more important.
But without me they wouldnt even had their album done, i worked so long on the album, and then they started bitching.. but Now i get the album and I get in for free! But they know that I won't do it for cheap next time.
Depends on the situation but, generally avoid business with friends. If you're working together, a new level of diplomacy has to be exerted if one is not holding their own. If they're coming to you to design stuff, they might expect a discount. It can work sometimes ... sometimes.