I think it's perfectly understandable that parents equate cheaper option with poorer quality....that's exactly the sort of game marketeers play.
It should be perfectly possible to produce a legal formula that meets all the national and international standards of safety and nutrition for a low price. But the industry does not want to. Someone has to pay for all the frills - the 'free' toys, the advertising, the marketing, the packaging, and the mega-profits.
That someone is parents!
Formula differs only by a couple of quid a pack in the UK. If someone produced a 'basics' or a 'no frills' brand, and pitched it at (say) £3 a box, would people buy it? I think they probably would, in the end.