Was thinking about buying the dell 2405fpw at costco online. But I want the 2407fpw. So what I was thinking is if i buy from costco can I return it when the 2407fpw and get a full cash refund? Do they pay for shipping it back? Also do I have to have a membership in order to do this? I currently dont have a membership but is it worth getting one if i only plan on buying the monitor there?