Unless anyone knows otherwise, I would imagine the answer is probably yes, you can, provided this doesn't invalidate any two-stage security checks your card provider uses.
If this is a company purchase I imagine you're looking for a new and properly guaranteed item. Personally I would never buy a macbook from an unknown seller on eBay. Manufacturer's warranties are often invalid for items bought on eBay, either because the item is a grey import or the seller isn't an authorised dealer. I would suggest checking this out before buying - ask Apple, not the seller!
