I would think timing is a factor. Example: * I buy inventory for $5, sell it for $10. * I buy more inventory, but it's gone up to $9. I'm selling for $13, b

I would think timing is a factor. Example: * I buy inventory for $5, sell it for $10. * I buy more inventory, but it's gone up to $9. I'm selling for $13, but still have some $10 on hand. * Wholesale plummets to $2. Until I've sold my on-hand inventory, bought more at $2 and sold that, I'm not making any margin, regardless of how low wholesale drops. I imagine the shelf-life for some stuff is short, but maybe longer for others.