Well, under perfect competition, the price *does* equal the marginal cost in equilibrium. The complaint that SMS prices are too high is legitimate in a situation where there is a high cost to entry preventing competition from driving the price down, as in the telecommunications industry. In these situations governments have a potentially important role to play (think about how other major utilities, like power companies, are run). So, yes, many folks may be willing to pay $X for SMS messages, but this may not be the socially efficient price due to the uncompetitiveness of the industry.

There is. It's called Congress.

technically 50% are below the median. if the distribution is skewed, then it is not clear what fraction would be below average.