This made me wonder: what if a restaurant puts a pain dough "pizza" for $30 on their menu?
Of course, no one would order it. But in this situation, an aggregator could offer it and the restaurant owner could take advantage of that.
It smells like fraud, except that every individual step seems legitimate (albeit weird). I'm pretty sure you're allowed to charge ridiculous prices for common goods if you so choose...
It still requires the aggregator to offer it for less that $30 (at least the cost of dough less). Which, at least in this case, seems to requires a scraping error.
That's not how this works. The glitch is that there's a particular menu-item mispriced by Doordash. You can't just order arbitrary things at arbitrary prices, and when the restaurant takes an order for X and delivers Y, it's taking a step towards making a material false statement to obtain something of value.