The Internet has evolved into a heterogeneous system, comprised of many users who value their own performance, rather than the efficiency of the system as a whole; as a result, proposals for network resource allocation must be robust against self-interested behavior of the network users. With this motivation, we analyze  network congestion games in which the users of congested links anticipate the effect of their actions on the link prices.  We discuss various mechanisms, all based on market-clearing ideas, some more scalable than others, and characterize the inefficiency of the resulting Nash equilibria compared to the social optimum.