Vending question?

As venders, what do you look for/expect from the venue when you agree to vend at an event? What about an event besides crowd size attracts you to it? Would you participate at a newer event if there is potential for growth?

My reasons for asking...my church has put on a Christian Rock concert for several years, but has always thought small. Crowds are around 200-250 people. But we now have a leadership team chomping at the bit to grow and do bigger things, so there is a chance this small concert (which has grown from 1 band five years ago to 3 bands this year, one being a new regional band that has a big following), could become a one day festival with 4-5 bands, with a larger headlining band, attracting upwards of 1,000 people. Up to this point, our church team and provided a meal during the concert, but I would like to get out of that business and open the event to licensed food venders.

So, I guess what I'm looking for is any info you vending guys can give me to help make a decision on how we should proceed. Do you pay the event a fee to set-up there, and how much? Does the event provide power for your set-up? What other amenities do you like to get from an event?

Thanks for your help guys.