Probably difficult to do a meaningful test. Drugstore and own brand films are/were made by the big manufacturers, and the drugstores sometimes changed manufacturer from time to time with no obvious indication on the actual product.

SFAIK all the own brand films which I've seen recently in the UK say "Made in Japan", which is obviously Fuji. No idea if they are just a repack of a current Fuji film, or an older version, but, logically, Fuji would not set up a separate coating run for a relatively small order. And I'm sure that hey would never deliberately produce an inferior or substandard product even under an own brand name.

(I'm not sure that Gold and Superia would count as "cheap" films....I'd say they were the "standard" consumer films. Color Plus and C200 would be the discount store ones, but even these are fine for everyday use with good processing and printing.)