I tell her NO.
About 5 minutes of negotiation commences. This includes her informing me that i am holding her money for her. I tell her no another 10 times. I tell her that she's got enough stuffed animals for three children's lifetimes, and she doesn't need another one. And it's also a waste of money.
Silence and tears.
When we get home, she draws me this absolutely adorable and heartbreaking picture of us in the store.

"No you can not have your money!"
Gosh, i love this little lady!