I mean, when that xkcd was made, that was a hard task. Now identifying a bird in a picture can be done in realtime on a raspberry pi in a weekend project.
The problem in the op isn't really a limitation of AI, it's coming up with an inventory management system that can detect low inventory without being obtrusive in a users life. The rest is just scraping local stores prices and compiling a list with some annealing algo that gets the best price to stops ratio.
Imma blow your mind, but all cars have this same problem. Literally any car that doesn't have ppf film on it should have bird poop and bugs cleaned off ASAP. It will discolor your paint, make it chip easier, or at worst make it completely fall off in that spot. Especially if you live in an area where birds have access to berries and stuff that can make their poop even more acidic.