It would be illegal to penalize the drivers, at least financially. I doubt the driver is given the choice of not buying the food based on price. If Doordash did

It would be illegal to penalize the drivers, at least financially. I doubt the driver is given the choice of not buying the food based on price. If Doordash did have some way to penalize them, they could just bounce over to Grubhub or others. Doordash is advertising food at a given price - they must sell it at that price, regardless of price of purchase.