I don't think fluctuation should matter too much. If the Euro is devalued significantly, European doctors will simply adjust to price according to inflation. If the Euro increases in value, the doctors will, again, adjust the price accordingly. However, if I was going with a European doctor, such as Dr. Guichet, I would pay in advance when the exchange rate from dollars to euros is low. Paying in advance when the exchange rate is $1.25 per eruo vs. $1.30 per euro is a difference of approximately $2,000!