"1,000 pesos which was worth about $80 now will not buy a coke."
I think you may need to check your math or your year. The exchange rate is now about 11.3 pesos to the dollar; which means, 1,000 pesos is worth $88 Dollars. It will not buy what it used to in Mexico and it certainly will not buy more than it used to - as your thoughts suggest.
I agree with you that the the Mexican working class are excellent people. The growth of their middle class at home is what is going to keep more people at home. That is the reason we do not have an immigration problem with Canada.
The election of Fox was an action by the Mexican people to create a fairer, more prosporus society. It is working and yes, it will still take some time.