There's no question that time is a very powerful influencer of prices. Most typically, time affects prices via inflation, the natural and inevitable tendency of things today to cost more than things cost yesterday. But that's far from the only way that time affects prices. A Love Is In the Air holiday pet is likely going to be less expensive to buy now than if you wait nine months from now. The cost of i397 BoE gear is going to continue to decay right up to the launch of the next expansion.
It's not a phenomenon unique to the game, of course. Those Super Bowl cakes are going to be a lot cheaper at the supermarket today than they were on Saturday. And if you can wait until January to shop for your winter clothes, you're going to get a far better deal than if you do it in October. A lot of prices are cyclical.
But how do those cycles work in the game? If you're a buyer of mats, when should you head to the Auction House to grab what you need? If you're a seller of ore, should just skip listing it certain days to maximize your profits? Let's see what the data say.