I think what the gentleman means is if he will get the real deal.
Yes Braveheart, as the guys say, at the border they will sell you either the real stuff made by Pfizer or a cheaper generic brand called MaxiFort with the active ingredient sildenafil citrate that Viagra by Pfizer uses.
Also, as they say, buy them at a big chain pharmacy like the one carried by Walmart stores.
Viagra by Pfizer will be more expensive in Mexico than in the US, but at least you can get them here cause you do not need a prescription to buy ED medicines in Mexico.
You can buy Cialis, Levitra and Viagra in any ammount you desire.
But, you have to be very careful if you will be mongering later on, do not carry your ED meds with you cause the police, if they hassel you, they can make a big fuzz about it (you don't need a prescription to buy them but you do need one to carry them on you).