This one is easy.
If you're touring, and you're:
A: Away from home,
B: An unknown, and
You needn't ask for more than 150 to 200 dollars. An even sweeter deal would be to suggest that you can take 10 percent of liquor sales. As far as contracts go, many venues will not sign one with cash in the terms unless it has been cleared with everyone in their venue. This is hard to do because they are busy, ALL OF THE TIME!
So, your initial contract should not contain a monetary guarantee. In fact it should only state that the venue will hold the date for you and not double book, if that happens, you are the rightful designee for the events of that date at that venue. THAT IS IT!!!