Probably not much cheaper no, also remember that
a) your friend would have to take time out of her schedule to go looking for them. I don't know how long she's out there for, I went for 5 days last year and it was only just long enough to do what I wanted to do let alone go round looking for someone else!
b) is technically only allowed to bring something like �175 worth of goods back from the states and I'm sure she'll be able to spend that herself if she's anything like me.
c) How much do they weigh as they could take her over her weight limit.
d) shoe sizes are different in the US, so she might buy them only for you to find that they don't fit!