Unless you feel that the US$ is going to completely collapse over night or before you get to where ever you are heading. I found it never paid for me to purchase Any foreign currency before arriving in the other Country.

1 of the thngs I used to Lovewhen I was purchasing the TCs back when, was at Macys in NYC the look on the foreigners faces when they told them how much they would get back when changing their money. Very few actually went ahead and changed their money. I think I figured out at best you lost 10% of your money

The best rates are usually via a withdrawl from an ATM over there but know what your Bank will charge you ahead of time. the Thieves (banks) have been dipping deeper and deeper into our pockets with flat $5 fees plus a 3% as well

In Aug in Italy the best rate was at The Hilton at the airport must be staying there. Then when my bags didnt arrive on another trip I was given 140 Euros. well just last week I sold the Euros I bought from the Hilton (same amount) an dgot my US$ back also in italy at a reg change place tahts how far the US$ has fallen since Aug