What to quote for 4 weekends at Pumpkin Patch?

I've been asked to face paint at a Pumpkin Patch every weekend in October, 6 hours a day.  They said they would work out an hourly rate with me so the customers only have to pay $1 per face.  Last year they had an employee do it, but she's unavailable this year.  The owner asked me after I face painted her daughter at a birthday party. I normally charge $75 per hour, and sometimes will do longer gigs for $50/hour.  Since this involves multiple hours and days, I'm wondering if I should give them a deal.  They said they would advertise for me.  It's a 45 minute drive to get there and I know it will wipe me out after 6 hours each day.  But if it pays well, it might be worth it.  It would be nice to have consistent work for a change.  Any recommendations?

Personally I would let them know your normal rate, and then dicker down to $50 if you have to (that is your discounted rate)--and tips. PP's can be hit or miss, depending weather, etc.--and you will be giving up the possibilty of booking higher paying events during those days. Remind the that you are covering your materials & insurance cost if you need to.