I've been getting my Grana Padano from iGourmet.com. Shipping costs are such that I wait until I have as large an order as I can afford. This is from their site:
"Grana Padano Stravecchio Oro del Tempo - Pound Cut - Stravecchio Oro del Tempo is a superior, 22-month aged Grana Padano produced by Agriform near Venice. This masterpiece compares beautifully with its better-known cousin Parmigiano Reggiano. The flavor of Stravecchio is intense and complex, with fruity overtones that evoke pineapple or strawberry, depending on the season. Like all precious things, every Stravecchio cheese is one of a kind, and each wheel is branded with a unique serial number. Agriform tests the quality of each wheel of Stravecchio every week until the twentieth month of aging. The end result of this rigorous testing process is that only the cheeses that deserve to become prime Grana Padano Stravecchio are stamped with the certificate of origin and guarantee."