We come from a rural area and have to drive (some times for a couple hours) to every gig. Our charges vary greatly. We have played folk venues for $150 minumun guarenteed against 70% of the gate. And we have played for all the gate without any guarentee. We like both those options because we draw well and usually make pretty good money. Though we have had bad weather nights that barely made us $50 a piece. We have also played for as little as $50 for the whole group in new markets for the benefit of an Art Assoc. or civic group or some charity. I don't particularly like doing this and usually think of it as a paid rehearsal and an opportunity to make new contacts. We won't play for free period. Playing small town festivals we want $200 a piece, willingly go down to $150 if asked and will accept $100 a piece if they won't hire us for more and we don't have another paying gig possibility on that date.
I have some friends that booked a small auditorium in a college town, hired a sound crew, advertised themselves, charged $10 a ticket (even to friends - no freebies). They cleared about $600 a piece after expenses. I'm impressed. My band is going to try it.
I also play solo. Nursing homes, parties, brown bag lunches at libraries, you name it. Most of these gigs are short 30 to 45 minutes. For them i ask at least $100 and almost always get it. occasionally i will play for $50, esp if it is close to home. Some business parties or conventions i charge more and almost always get it.
Here's what i do when a business calls about a summer party or a convention or a Christmas party or whatever for either me or my band. When they ask how much we cost, I ask how much they have in the budget. If it is way higher than we normally charge i drop it down by a few hundred bucks and tell them that they are lucky because we can save them some money. If their budget hits our target, i tell them that is good we will play for that. If it is lower than what we want, I try to get them to think about how much we add to their event and try to get them to come up. They usually do.
all that said: it is a lot easier to play than it is for me to deal with the business end of this music business. And i keep the fact that i am doing it because i love it in the fore front of my mind. And therefore, our fees vary greatly.