I am not fancy in the slightest ;). I usually get my hair cut four times a year at Supercuts for $20 a go. However, I've been wanting to try a keratin treatment, so when a deal came up for a local salon for a treatment with style and cut for $164 - 20% off = $131.20, I nabbed it as a Christmas present to myself.

Their current offer states that the value of the deal I bought is $350, and they're now charging $184 for it through Groupon.

How much am I supposed to tip? I know it's supposed to be off the full price and not what I paid, but is it 20%? Is there a cap on how much? (20% of $350 just seems like a hell of a lot of money!) I will assume there's a separate shampoo person, and that they get tipped separately. $5 for that?

Please help a clueless bee from not being too horribly awkward