Suzhou numerals are mainly applied in accounting, not marking prices. If you travel in some traditional south China countryside and are lucky enough, you will see these numerals are used to mark doors which need to be listed in orders at night.
Maybe you need to ask right person in Chinatown. I assume senior Cantonese know Suzhou numerals better than youth generation. Or such numerals, like abacus, have become extinct today for some reasons, for example computer application in business, but still kept well in English memories about Chinese stereotype.But it is amazing to see them again in telly,which recalls my costy memeory about my childhood.