Some folks don’t shop with phones.
Two options:
Yell “Price check!” every time you want to know a price.
Bring multiple items to checkout and then buy just the ones that scan a price you like. You’ll need a big cart.
I did the latter ONCE when a random pharmacy in a city I was visiting had NO prices on ANYTHING and I just wanted deodorant and toothpaste. I didn’t know how much anything was and there was no one to ask, so I brought a dozen deodorants and a dozen toothpastes to the checkout and had the checker scan each one for the best price and let them re-shelf the rest. Hey, wasn’t my idea.
Well done! Would have made a billion hits/views on youtube/rumble!