If it is a "real" (PSTN) phone number, then the caller would pay whatever their provider charges for that call. If you are talking about a Skype user "calling" a Skype "name", then, if it works, and I'm not certain that it does, there would be no charge. There had been some discussion in the past, about Skype connect not allowing "regular" Skype users from calling. You'd better check with Skype to see how this currently works, there may have been some changes recently. You would have to be assigned a Skype name, and not just a phone number, reachable by any other Skype user, for it to be a no charge connection.