[harvey9]

I think it's almost achievable if you say 'cheapest with 4 or more stars and delivery tomorrow'. Problem remains that cheapest could be the smallest pack size or cheapest per pound, and Amazon is not good at the latter anyway.

[danpalmer]

It is, but it means engineering your formulations carefully before giving them to the computer. Computers taking things literally isn't new, but there's normally less on the line when we do it.

Also I would imagine that as often as not there would be an opportunity for human judgement. Maybe there's a _much_ cheaper one at 3.98 stars, or the 4+ star and next day delivery options are 3x more expensive than the next available option. In both of these cases a human with the right intentions would likely stop and do something different.