How to price a personal FP session!?

I'm getting a lot of requests to do singular face painting sessions for halloween, but I'm not sure how to price them!
I charge $75/hour for birthdays, but what if I was doing a whole zombie face with liquid latex & it could take 2 hours, if it fair to charge $150?
If I charge less, I feel like I'm selling myself short because of my normal hourly rate.

Yes.

I figure out my time required for specific types of service, and price them accordingly.

Face only make-up - adult (face paint!) - $35 (15-20 min)

Character make-up with ONE sfx (burn, cut, or application of ONE piece) - $65 (approx 30 min)

Full application head/neck down to neckline and make-up - $100 (hour) If longer than one hour they pay hourly rate.

If they want arms/chest, etc. starts at $150, with hourly rate second hour on. I have a couple of regulars that do a three hour booking.

Prices are at my location only - I don't travel on Halloween due to lost time!

Thanks so much!!
I never thought of pricing them in that sort of way!

Did my daughters face with liquid latex and tissue mix and tore away randomly ..... 3 hours to complete to shoot a video for the 15 Second Horror contest

lol, always get a video or pics