same prices whether macy's or website, the only difference is on the website you tend to get little extras, like the mascaras and the samples. my macy's and nordstrom are hit or miss whether they give out samples, and its usually what they choose for you, whereas online you get to choose.
if she doesn't wear shadow, I wouldn't get her the palatte because its 2 tiny shadows and a tiny liner.
I suppose if you are looking to save money, you could always get her a cheaper brush from a drugstore (assuming they have the same style brush) and she could get herself the pricier one if she really wants it. it sounds like its the actual liner that she wants, so the one for $20 would work out great for both of you!