If it is to touchup the bride only - the rates depend upon what you want for your time - it's that simple. I charge a flat rate for day up to 10 hours total - you can start so early with a bride and party that by the time you get to after the ceremony and into the reception it's 16 hours and up - so you have to nail down the hours in a contract preferably - i charge day rates for the day and if it's over 8 or 10 hours total it goes UP. I charge 1000.00 for 10 hours on the wedding day. You have to do your research and determine what your time is worth for that service - nothing I can say other than that.
You are talking about driving around a lot, packing and repacking your kit and touching the bride up on the fly in a lot of cases, so... you charge what you think your hour per that day is after - is my advice. You have to deliniate start and end time, or you will be there FOREVER and they will always ask you to touch others up too - while drinking and partying - so do be aware.
Agree with everything.
Please nail it done in your contract. I have it, where I only touch up people who I did makeup for. They got me once and I was touching up everyone that wanted a touch up.