Sante Fe comes to mind but perhaps a little cold in the winter but otherwise meets other criteria. Albuquerque is right at 5,100 feet, has loads of open space and trails and easy access to lower elevation and pretty mild weather and very affordable housing.
It is a city of over a half million so there's a lot of restaurants and entertainment options and has a big enough airport to get by but not a lot of nonstops.
Reno is at 4,500 feet is only 20 minutes from Tahoe and much higher elevation, has gotten more expensive lately but still affordable compared to most running meccas, especially so if you live in the burbs, lots of entertainment and decent restaurants. There are trails within city limits and the options for trails are pretty much limitless within an hour drive in any direction.
Bishop CA elevation 4,000 but one can drive to over 8,000 in 20 minutes is also getting more expensive but you can still rent a 1 bedroom for $1000 or buy a place for under $400,000.
El Paso varies in elevation and while the airport is at 4,000 feet North Franklin Mountain at over 7,000 feet is within city limits and has an extensive trail network. Housing is super inexpensive, average high temp in Jan / Feb is in low 60s, great tex mex and Mexican food scene. It is not for everyone but it has a lot going for it in terms of cost and access especially since UTEP has a great track tradition and there's lots of options for finding a track to train on.