Home Depot also keeps the price propped up by starting and stopping the plants where it's made. They seem to be happy with a price for 7/16 at around $10. to $12. I'm glad Lowes is in the game too, or the price would be higher.
When I built my home a few years ago I caught a dip in price and bought hundreds of sheets of 7/16 for $4.50. It took over 300 sheets just to do the roof in a crosshatched layout of two layers, then I sheeted the exterior with 19/32 and almost all of the interior walls too.
I doubt there is any shortage of raw material right now. Just wondering, but I wonder what the affect of the beetle killed forests in the West has on the supply? There are uncountable millions of dead trees in the forest now and there is a shortage of mills to handle the influx.