My kids know we're poor
, when they ask for something that is pricey, I never hesitate to explain to them what expensive means and how we just can't do it right now. If they bicker about it, I ask them if they'd rather have a mommy that works and buys them nice toys while they go to a babysitter, or a mommy that stays home and plays with them and picks them up from school, etc. They always pick me staying at home with them. I also tell them to save their money for things that are really expensive. One year we were really strapped and I bought them like a 2 dozen things that cost like $1-2 each and individually wrapped each one, they had a ball unwrapping all these silly things and they really played with all of them. Xmas time is a good time to reinforce the values of your family, and it doesn't have to include that really expensive doll. Although I know how you feel and that you'd really like to get it for her...
How old is your daughter?