Thanks so much for your explanations. so i should first logon to paypal to configure this first. Then create my buy now button either at paypal or BV?

If so, after setting it up in pp, will it automatically add to the particular button i intend to create at any time or do i have to do any other thing or configuration to make it work. Again what is meant by "base shipping" & "extra shipping". I don't really know how it works.

Thanks for your help.