After spending most of the year between 11.50 and 12 Pesos to the dollar, the Peso has weakened considerably. That's good for tourists and bad for residents in general. At the moment the rate is about 13.43 to one dollar. So, if you are going to visit you need to pay in Pesos as much as possible. Either use a credit card (check fees and exchanmge rates) or get cash at ATMs. NOT the time to try and do math on the fly with dollars or Pounds.
