If not at the market, ideally you'll gather yours from a more generous species than the Eastern white pine.
For kicks, and with no expectation of uncovering an economically viable food source, in January I gathered three dozen fallen cones in Stamford, Connecticut, and spread them in metal pans on my Manhattan radiators. After a few short hours of piney freshness, I gave the cones a full day, and then some, to spread their scales.
Female cones shelter two nuts under each scale (botanically they're seeds, not nuts), which in this species wear a flange that helps them flutter some distance from their parents. You can see them in the first photo below, and in the second, which shows part of the pitiful harvest following an hour of tapping, bending, peeling, and prodding. What looks like a small apple seed is actually a shell encasing a single, even smaller pine nut; the whole is edible, with a vaguely resinous taste, though not very palatable. Splitting the shells to expose the nuts themselves would have been possible only with more patience and, perhaps, smaller hands.
From Eastern white pines, Stamford, Connecticut