I was going to suggest an allowance...1 toy and the money is nearly gone... Well, that's the way it works, right? And stuffed animal after stuffed animal... That's her choice! If it is HER money, then it is her choices and when it is gone, it is gone. She might not understand the whole thing, but she will start to understand "I have enough money"/"I don't have enough money". It also takes the responsibility from YOU to be "the bad guy". Now if she gets the toy or not it is her
choice but it will cost her. She will learn (my guess is pretty soon) about choices and saving. And your judegement if it is "worthy" doesn't make you the bad guy either. My son (4 yrs old) has bought all sorts of things I would have thought rediculus with his allowance, but they turned out to be really important to him.
For us, we do a hybrid system- $1 a week given (this is ususally enough for a small "happy thing" but not too much to really waste and can save up fairly quickly for "bigger things" he wants). Then, he can earn quarters by doing "extra work" (setting the table, helping in the garden, helping clear the car of snow, putting away laundry, etc.). This allows him to control the flow to some degree. If he wants something "big" faster, he can work a lot. We've also on occasion done some micro-credit, but we are careful about that
I put very few restrictions on what he can buy. It cannot be violent (guns, swords, fighting fists). Period. Anything else is fair game from snacks to toys.
He quickly learned to make choices and figured to save. He also sometimes splurges and that is OK too. He's learned to compare prices and starting to understand the money values.
We now don't buy a lot of things for him. He gets "big presents" on his birthday, Hanukkah, etc. but for little trips to the store, trips to the zoo gift shop, etc. its his money that he must spend.
Before, we had a ton of tantrums and whining. Now, no more fights and he is learning a lot about how all this works.