I'd tip $15 (pay $95). $12 is 15% and $16 is 20%. Going to $100 would be nice, but 25% seems like a lot to tip.
I once tipped a hairdresser 100%. I had moved from a city where my hair cost $100 to cut. She straightened my hair to cut it for a donation, used a hot oil scalp massage, then washed it, got a hand massage while conditioning, cut it, styled it- I was there for about 2 hours. When she finished the receptionist told me the total cost was "twenty". I actually said "dollars?" I was so baffled. I made sure she knew I had the extra services, not just cut- she said yep, included. I was so convinced they charged me the wrong amount I left $40. Nope, next time I went, it was $20, so from then on I paid $25. Sadly I moved and can't get that kind of salon pricing anymore.