My other daughters 5th birthday party?

my daughters birthday is on the 26th june and she wants her party at the build a bear factory she has chosen 10 friends plus her and her sister and we have said that they can have a bear up to the price of �15 each plus she is having the mascot thats �20. Has any bodies children ever had a party there or been to a party there and knows can the children mix and change (if u get what i mean) say they want a cheaper bear can they brings the price up to what we have set by getting bits for the bear or is that seperate? Also is there any other cost that i have to add or is it just per child and the mascot thanks (sorry if its confusing)