Mandatory to buy, but available from a choice of competitors with adversarial interests to each other. IMHO, an adversarial bidding process (under control of o

Mandatory to buy, but available from a choice of competitors with adversarial interests to each other. IMHO, an adversarial bidding process (under control of one party) is no replacement for a strategic adversary (capable of planning and executing strategy). The former may prevent the most egregious price raises, but it's insufficient for creating the broader competition that ultimately drives prices down.