Sources of vermiculite in northern Virginia

At first I found out that vermiculite is almost impossible to find here in northern Virginia. After searching for a day or so I eventually found a few suppliers of it:

• Meadow view farms in Woodbridge has the fine variety…the kind they tell us to stay away from  4 cu ft bag for $25
• Home Depot has 2 cu ft bags of the medium variety for $21
• Merrifield Gardens in Fair Oaks has the 4 cu ft bags of coarse vermiculite for $40
• Roxbury Farms in Fredericksburg has 4 cu ft bags of coarse vermiculite for $27
• Southern States in Manassas has 4 cu ft bags of coarse vermiculite for $18