"Buying" might be a generous term, depending on what the rate of inflation actually is here.

The boy takes another ice cream sandwich for himself and goes to sit on the cart's step with it. "You like it?" he asks, taking a bite of his own. It's special, sure, but it's not any kind of exceptional luxury in his mind. People have ice cream all the time! Just not him, unless it comes to the park. That's fine, though, because it does sometimes.