DJ Pete,
Like I said it is really going to depend on where you live and how much they can afford to pay for the amount of time they want you.
Now, if they don’t want to tell you what they would pay, then make them an offer for what you would be willing to do it for. Then if they think that is to high or can’t afford that much, you can always come down and meet in the middle with them.
Above all, don’t sell yourself short just to get a gig though. Maybe too, you can ask around and see what other DJ’s in that area are getting and base your price from that. Either way, good luck and keep playing!!