Greeting's, I've recently moved back to the states after living nine years in mile-high Oaxaca, Mexico (My kids are stateside for high school.)
Oaxaca is a great running environment with endless natural beauty to embrace, and training opportunities from 5000 to 8000 feet. There is also an active, surprisingly competitive racing scene. I've posted my guide to Oaxaca running here:
http://thegrumpyrunner.blogspot.com/2017/02/oaxaca-running-tips.html
The ruins, culture, history, artisan mezcal, art and especially the food are outstanding. And it's pretty inexpensive.