Builders rarely sell for over book. this is because the barrier to entry in zero and their is no economic moat. Other industries trade at a premium to BV because of a specific technology or brand name or large barriers to entry. If anything the Builders should be selling at less thanbook because their names have been dragged through the mud. RYL book value is probably over stated by at least 250MM also. Look at the sales by CTX yesterday they bought the property for 900MM is was listed at 528MM on the balance sheet and was sold for what 160M. balance sheets of the builders are still way overstated.
I think Drugs point is if he wanted to buy RYL he would first look at book value then start adjusting based on future revenue growth, market conditions, PE and so on and so forth. He would then conclude that RYL is worth about $15/share. However looking down the road at what might be their losses for the year he decides to wait and pick it up much cheaper.
Homebuilders/realestate co's trade in relation to book value more than other industries. The goal of such a company is to grow book value. They are asset plays. Typically homebuilders trade close to book value and very low PE's.