Pricing Gigs Out of Town

An acquaintance wants me to paint faces for her daughter's birthday party in a few months, but it's four hours away. She knows it's going to be pricey, but still wants me to go. I just don't know how to work out the cost. Any ideas?

So here's kind of a starting point:
https://www.timesheets.com/blog/2016/05/pay-for-travel-time-reimburse-mileage/

In addition to your rate for painting at the party, have a rate for driving/travel (when it is outside your home territory) that covers mileage and your time. For me, my home territory is 20 miles. I charge extra for anything farther than that. While I'm driving, I'm not using up my supplies so I don't charge my full hourly painting rate but a lower rate. Keep in mind that I'm also not available for other work so I need to consider how much could I have made if I had other jobs that day too. On the other hand a booked job is better than a potential job.  

For simple math, let's say you charge $100/hr for painting and $50/hour for driving.

If you drive for 4 hours each way and paint for 2 hours while you are there, that would be 8 * $50 + 2 * $100 = $600. Will you also need a hotel?  food?
Add that too. (And adjust the numbers for your rates.)

Now you may feel that this is a good friend and you want to give her a discount, and that is your choice. But she knows you are committing to a really long day to paint at the party.

$600 for 10 hours averages out to $60/hour. Are you OK with that? What if it is on a busy Saturday where you turn away other parties/jobs? Are you that busy and well booked? What if the party were on a day that wasn't as busy like a weekday? or Sunday?

Fantastic answer!

This helps so much! Thank you!

How did this wind up going?