Because there was no pressure to force the price up toward it’s maximum support level.
You’re absolutely thinking about how prices move around the right way. I was perhaps trying to make too fine a point.
What you’re describing is how markets move around without liquidity constraints. That is, the prices are being set when the market makers have a lot more wealth than what they are willing to pay; they could pay more, but choose not to because they don’t value the item any more highly. When that’s the case, prices will tend to reflect fundamental market values.
What you mentioned before was people essentially bidding at the edge of their ability to pay; they may value the item more than that, but they just don’t have the funds available to bid higher so they bid everything. When those guys are just a handful of players taking a more or less well established market price it’s not a big effect, but when there’s a serious shortage of currency and those players are the market makers things behave quite a bit differently.
Basically, when bids of ‘everything’ are the high bids consistently it’s a signal that an item is really underpriced; its fair market value without liquidity constraints would be much higher, but no one can actually put that amount of money together so the high bids come in well below its real value.
This matters because the highest of high end items in a game economy will often suffer from this problem for a long, long time. When the trading post first went live a few days after launch, precursors were readily available on the TP for around 20 gold. Is that because that is all people valued them at? Of course not. Clearly they were worth more than a couple days of farming even back then. But that’s all people could scrape together, so the high bids were ‘3 days of power farming’; the next day they were ‘4 days of slightly less efficient power farming’, then ‘5 days of even less efficient farming’, etc, etc.
They were consistently underpriced for months until a decent chunk of the player base got rich enough to buy them outright without blinking. Combined with people figuring out the forge prices on precursors finally started to stabilize at something resembling a liquid market price.
Point being that free markets won’t always price things fairly when there are liquidity constraints, and you can’t trust a rise in the price of very high end items to reflect inflation or anything else of the like; there’s a stronger force at work there.