I keep my grain at a friend's house, so I don't know for sure how much I've got. A rough guess would be in the 700-1000 lb. range total.
Curious if you use it fast enough before it goes stale, and/or if you have storage advice to keep it fresh? I don't find it worth the while to stock up unless I'm going out of my way to find something not normally stocked, say organic base malts.