That's why user-scripting makes sense!

The downside, for the vendor, is that I'd also wind up scripting price-searching at multiple local grocery stores for equivalent items. If I can just curbside pick up what I need at both stores, they're literally next-door to each other.

The irony is that if those two stores were to cooperate and work together on a unified scripting system, both would gain sales on average; yeah, if an ear of corn is 50¢ at Safeway and 75¢ at Raley's, Raley's would lose that sale, but if Raley's happens to also sell mayonnaise for $1 v. Safeway's $1.50, and I can order both at the same time to fruitlessly attempt to satiate my insatiable hunger for elotes, then both would get a sale (and same deal if one or the other is cheaper on the chili powder and/or cotija).