What you will accept is entirely up to you (like a band - I know bands who get paid anywhere from $250 - 4000 depending on the venue!)

In your case, if you are unknown, you may need to start small and work up. I don't know if there is a status quo for DJ's - I would say ask friends who DJ - depends on where you live, the clubs, the night, etc.

You can also do some roundabout research. Call DJ's in the yellow pages and anonymously ask their rates for various things. For a hot club on a Friday night you'd ask for more than you would on a Tuesday night at a small little place you know?

Always get fed if the place has food :)

This is where you have control and set a range in your mind. Whatever you do, try to research it first. You don't want to over or undersell yourself. But sometimes taking a smaller gig or less money on a hot night at a venue you are dying to spin is worth it to get noticed. Same goes for us all :)