Tipping

I am getting cyberhair on Saturday (as I've said on a  previous post) which will be $1400. How much am I supposed to give them for a tip? Is it standard to give a large one? I was thinking of giving her $50. Is that enough? 

I depends of their level of serice to you and how happy you are with the results.

If they do well, go ahead and tip.
However, if service is bad, dont tip at all.

Please dont flame me for this! This is just my opinion.