I have a contract with TelCel and the plan is amazing. My cell bill is about 500 pesos (divide by 18 for us dollars) a month which includes my phone cost and it works amazing everywhere I go in Mexico or in the States. It automatically uses ATT when its available in the States. No charges for data up north. On my trip to Italy and Spain this year I received an email from TelCel that offered me the EU plan for 30 days for about 300 pesos extra so I used my phone and had no extra fees hidden in my bill.