If you are going to Mexico, then why not head for some places that are off the beaten track, rather than your pre packed tourist resorts where you will find nothing authentic? I would suggest Vera Cruz, which is a lovely port for visiting and there are many things to see.
I heard that Vera Cruz is a huge city in fact! I will not go on holiday to Mexico, at least not as such - I am going to travel around the country in a back packers type of way. I am hoping that you can give me some tips for budget accommodation and food while I am there?