Be prepared for long delays, shipping issues, or them selling items they don't have. They will sell items that they don't stock and have no ideas when they can get them to you. This is Optics Planet and their customer service is HORRIBLE for Dvor.
I think many of the things they offer good prices on are essentially pre-orders. The deals run for a certain amount of time and when the sale is over they place an order with the manufacturer for the number of items sold. If you're not in a hurry, you can sometimes get very good deals. I've ordered from them on several occasions with no issues.