-As far as I remember from Economics in university: Price goes down, demand goes up, 100% of the time.

Not to get picky about this point, and it is likely not germane to this topic of health care, but can't help myself

Sometimes if a seller increases the price of an item, the demand actually goes UP

such an example would be so-called luxury items, like jewelry, high-end entertainment gear, or a Hollywood real-estate property

There will always be someone who perceives that if something is more expensive, therefore it is better, and rich but foolish people look at the price and make a judgement based on that