If you are reading the San Miguel Times while sitting at home in the US, you need to know that you actually can fly from Los Angeles into Guanajuato/León (that airport is about midway between the two cities in Mexico, in the town of Silao) for only $265 USD on AeroMexico.
The Silao airport is only 105 kilometers (68 miles) west of San Miguel de Allende
Fare: LAX to Guanajuato/Leon, Mexico, on AeroMéxico for $265 round trip, including all taxes and fees.
Restrictions: The fare, subject to availability, must be booked by Oct. 7. It is for travel through May 19.