The extreme underpricing strategy is actually frowned upon by the majority of real estate salespeople and brokers, believe it or not. There are always going to be agents (and brokerages) who firmly believe in this strategy. I don't believe for a second that the sellers ultimately decided on that listing price. They would've had a discussion with the listing agent and perhaps agreed to price it lower than market value to draw more interest in a short period of time but I believe the actual figure would've been determined by the agent.
Listing lower than market value is fairly routine but we're normally talking about maybe 10% max, and keeping it under each $50,000 increment. One major issue is actually the buyers and their agents, in my opinion. If you see a house that's worth say $500,000 and it's listed at $300,000 and you know there are 20 offers already. Why bother putting in a figure of $320,000 or dare i say it even $400,000? That extra bid is only going to drive up further offers. Buyer's agents need to know when to tell their client that their offer is not only a shot in the dark but counter-productive for the future buyers. The most valuable piece of information is simply knowing how much that property is actually worth and aligning that with how much one is willing to pay for it. Excessively low listing prices are skewing the sold numbers because buyers are hoping to score a sought-after property at a price that is otherwise unrealistic.