Well there JoJo! It used to be a ratio of 10 Pesos to $1.00 …but since the economy has gone wacko…it's changed somewhat…as of today 10 Pesos is equal to about $0.79…or $1.00 = 12.70 Pesos
As far as customs goes…getting through in Mexico is the red light/green light system…red light you get searched…green light you go through. And yes, there are "time share" guys in the Ixtapa/Zihuatanejo airport too (though not as many)…just ignore them as JoJo said.
When leaving…Mexico has always done the extra searching through bags prior to the x-ray/security machine and they usually search again prior to boarding the plane…guess we'll all see what new security plans lay ahead!