Doesn't quite work like that. There are rich players and some will actually do that but they're rather insignificant compared to the total pool of CE available amongst all players. There's plenty factors that determine the price, here's a couple noteworthy ones:
- The "value" of crowns, and more specifically how useful they are to players. Because CE is traded in crowns, the more valuable crowns are, the cheaper (in crowns it will be to buy CE). To decrease the value in crowns of CE, the easiest solution is to create crown sinks (such as Variant rolling), which is features or else that revolves around paying in crowns (to the game itself, therefore destroying the actual crowns paid), a good recent example of that is the various featured auctions of rare goods on Auction House. This applies to Energy as well (supply depot is an example of Energy sink)
- The supply of CE and it's "buy appeal". Right now CE can only be "created" by purchasing directly from Spiral Knights using your currency of choice. There used to be a time promotional offers included prize boxes with CE bundle which gave a strong incentive for players to buy Energy, therefore increasing the supply and reducing the overall value of CE in crowns.

There's times where the energy prices seem to peak (low or high) for short amount of times (a few hours at most), it's usually due to players trading significant amounts of energy or crowns over a short period of time; they don't really represent the overall trend for values but it can give you an idea of when it is a good time to buy and when it isn't.
Ah and of course illuminatis.