How much should 1 person save up for disney world for 1 visit?

My family & I are going to Disney World while in Florida at the end of Sept this year. I am required to pay for myself (adult). I'm not sure if we are going to Disney World all 3 days that we're down there or just one day. No need to worry about the hotel because that's already taken care of. So I just need to know how much to save up for this trip for 1 person (airfare, food, souvenirs, & etc).