Pros for DMU: about $60,000 less in tuition over 4 years, plus you will have a much lower general cost of living
Cons for DMU: that lower cost of living comes from the fact that you live in Des Moines, Iowa
Pros for AZCOM: if you're not into primary care, they're one of the more specialty-friendly DO schools, plus Glendale is more fun than Des Moines
AZCons: significantly more expensive; you'll probably spend in the neighborhood of $100,000 more throughout the 4 years