There is an active conversation thread in the Second Life blogs:
What is the current rate of service charge for DJs
If you're interested, have a read. There are many valid points from various people. The discussion is in regards to the "average" pay for a DJ in Second Life, and why a DJ/performer may or may not charge for an event.
Just wanted to bring it to your attention if you are a venue owner, a booking manager or agent, or a DJ looking for gigs in Second Life. This thread is also relevant to live musicians, singers, and performers as well.