It got a little tin-foily in the comments to your question so here is some founded patterns:
Surge pricing - If a store uses the e-ink or other changeable price tags on their shelves, they can change the price of certain items based on just general anonymous shopping patterns:
A spike in the purchase of Frosted Flakes over the last x hours or days
or time based patterns, say people shop for breakfast foods more in the morning than at night,
Prices can increase or decrease based on those params. It's unlikely a store has cameras to track you to an aisle -> shelf -> product to quickly change the price, and then remember to charge you that price as you are tracked back to the register - there is really no need for all of that. Global heuristic based pricing described above is good enough.
Individual Dynamic pricing - If you use a store's app to purchase for in-store or curbside pickup, the prices in the app might not be the same prices in the store - they could under or overcharge you based on your previous purchase history in the app.
You won't have to dive deep on these practices, any MSM outlet has covered them. Whether Wal-Mart is using these practices, I could not say with authority.
It got a little tin-foily in the comments to your question so here is some founded patterns:
Surge pricing - If a store uses the e-ink or other changeable price tags on their shelves, they can change the price of certain items based on just general anonymous shopping patterns:
Prices can increase or decrease based on those params. It's unlikely a store has cameras to track you to an aisle -> shelf -> product to quickly change the price, and then remember to charge you that price as you are tracked back to the register - there is really no need for all of that. Global heuristic based pricing described above is good enough.
Individual Dynamic pricing - If you use a store's app to purchase for in-store or curbside pickup, the prices in the app might not be the same prices in the store - they could under or overcharge you based on your previous purchase history in the app.
You won't have to dive deep on these practices, any MSM outlet has covered them. Whether Wal-Mart is using these practices, I could not say with authority.