What was your response when she asked you Maddy?
I think if the delivery of the request was different, I wouldn't feel as annoyed
The interesting thing here Maddy is that she did not come to you FIRST . You could have given her "mates rates" or not. Or it would have given you the opportunity to say it will be your gift but the fact that she found it was expensive and then came to you to you as a cheap alternative and obviously second or third choice is poor form.