What do you mean by "market"? Who is the consumer? Don't say the cable/dbs customer. They clearly aren't the consumer. They aren't choosing whether or not to buy a particular station.
Sorry, but I am going to say the customer. The providers assemble packages of channels which are sold to customers. Most people have the choice of going with a local cable company, D* or E*. Each one of these providers offers multiple tiers and options.
The channels within those packages and tiers, with the price of each, is what makes the ultimate product (i.e. a subscription) attractive to the customer.
Too few channels, doesn't attract that many customers. Too high a price for the perceived value of the package, likewise.
Thus in the end, it is customer demand for the channels, combined with the price they are willing to pay for the service, that drives the price of each channel.
A channel that has low ratings, or one that viewers don't care much about, cannot demand a premium price. They can try to demand one, but no one will pay it. A provider would drop them and elect to withstand the complaints from their customers.
In the case of the BTN, there are a certain number of customers who really want the channel and will put pressure on their providers to offer it. So the BTN is attempting to use that leverage to generate the maximum amount of revenue. If they set the price too high, they run the risk of alienating their own customer base and having them side with the provider's management. If they set it too low, then everyone will carry them, but they won't generate an acceptable level of revenue.
The same is true for every channel. I'm sure the E! channel attempts to get every last dollar they can squeeze out of the providers and advertisers. To charge the most they can without having D* or E* or Comcast or whomever drop them from their lineup.
In the end, it all comes down to customer demand and maximizing revenue.
