Perhaps you are in the mood for "Jen on a (your) stick"?  haha  Sorry, I couldn't resist!

I help run a (wholesome)booth out at the State Fair.  This makes my availability this week short and not as available as usual.  I appreciate that you'd be willing to bend your schedule to work with mine and for doing so I'd like to offer you $50 off my regular rate!

Mon/Wed: 2-3pm
Tues/Fri: 10am - 2:30pm
Thurs: 6:30pm - 11pm
Sat/Sun: 9am - 2pm

~Jen