The slope of the demand curve (everyone has a different price point) does indicate that in theory the price necessarily comes down. If the price doesn't come down, it means X (stupidly) wasn't maximizing profit, but for all intents and purposes, we should expect them to maximize profit.
X maximizes profit based on the price 100 people who value the widget the most will buy it for. The remaining 900 people who demand it are waiting for a lower price (people who buy the iPhone from AT&T vs those who wait to get it on T-Mobile). They may not be getting market equilibrium pricing, but most certainly the price is coming down.
Your example reminds me of Tickle Me Elmo. This is the way that usually works: the manufacturer contractually obligates its competing vendors to charge below a certain price point. They could have initially charged a lot more, but the buzz that is created makes more money in the long run for the manufacturer...the competing vendors however would have charged obscene amounts when the supply was scarce, had they been allowed to.
Agree with the supply and demand curves, however, there are two points to make with regard to these curves.
1. These curves are built with the ideal assumption that all actors in the situation are rational and well-informed. We know this assumption does not hold. So, supply and demand curves never fully explain prices.
2. We have to understand 'price' as not merely nominal dollar amounts. Prices include the costs to the consumer of traveling further, of making a left-hand turn as opposed to a right-hand turn, etc.
I'm not sure exactly how these points play into the healthcare debate, but I imagine they play a role.