But this was far more interesting. The fact that Doordash scrapes prices, and apparently doesn't verify... how does this happen?
I'm not familiar with the reimbursement model. I'm assuming the driver pays with a credit card, and Doordash reimburses this amount. Regardless, there will now be database entries for a customer paying $160 and Doordash reimbursing $240.
What happens in a company that allows $80 to vanish like that? Unless this is an incentive (I'm doubtful this was deliberate). Wouldn't one of the first things you do is validate your financials? In which case, is the driver getting screwed here? (They charge the customer $160, and reimburse the driver for only that amount)
If not, this opens up a huge potential for fraud. There is a semi-popular YouTube video where some young British folks set up a 'restaurant' in their home kitchen and successfully list on a delivery app. They deliver several orders (reimbursing the customer of course). If it's trivial to get listed, and potentially with the wrong prices, then it's trivial to launder money this way.
Set up a fake restaurant, deliver little/nothing to a known party, profit. Now, maybe it would become obvious if you made the same orders or within the same time frame. But again, trivial to generate randomness.
What protection do these companies actually have against fraud? By nature, they're assuming trust, and this is exploitable.