> it slows down how fast the supply sells out

This is not the goal. The only mitigation that could make sense is to impose limits per person or household to avoid someone hugging all the supply.

> This allows there to always be supply available for purchase

By the very few who can afford it, by definition of raising the prices until the products barely sell. If you have 100 items and 1000 people you guarantee that at least 90% of people won't get an item. It doesn't matter if it's because there is none left, or because it's too expensive. If you're hungry because the shelf is empty, or the shelf is full but you can't afford it, what's the practical difference for your stomach?