"Can I have this stamp?" "You can spend your allowance on it if you want."
"Let's get the yogurt crunch bites!" "You can spend your allowance on it if you want."
"No, don't return the pot!" "It's thirty dollars. Do you want to spend your allowance on it? Oh, you don't have that much? Too bad."
For whatever reason, she totally accepts this as a reasonable answer, and it silences her, whereas before, we'd keep getting the repeated whining "Please? Please? Please!"
On the other hand, she's terrible at taking care of it. Whenever she wants to buy something she can't remember where she put her money, and has shown no signs of learning to be careful. I suppose she'll learn eventually.
And on the gripping hand, $5 a week was too much. $2-3 probably would have been about right. That very first purchase - Flock! - I should have gone in with her on it or something. What I've been doing to compensate is to only give her her allowance each week if she actually remembers.