It shouldn't actually make any difference as skype doesn't work that way. If you are making skype to skype calls then it's free anyway. And the cost to phone a particular country is the same no matter what your home location is or where you are actually calling from.
One thing I have noticed is skype's rates were obviously set when UK Pounds were a lot stronger so for example it's cheaper now to pay for calls in UK Pounds rather than US Dollars or Euros.