Hi Mike,
Auction Sniper shipping insurance can only be purchased for items that are won using our service so, since Auction Sniper cannot be used to purchase "Buy it Now" items, you will not be able to purchase shipping insurance through us for the shipment of such items.
If you place a snipe on an auction item and you forget to check the "Include shipping insurance for a small fee" box when adding the snipe to your account, you can still find the option to purchase insurance after the sale by clicking the "Modify" button next to the snipe. As long as the policy is purchased within 3 days of when the item is shipped, the item will be covered.
If you have any additional questions or concerns, please feel free to contact our customer support team using the web form on the following page:
http://support.auctionsniper.com-Mike