First time buyers: Please help!?

We'll be moving to the DC area (where the cost of living is SKY HIGH) We're in the military so BAH may cover some of our mortgage. We'll be stationed there for 3 years so I don't know if its worth it. I checked around for cheaper places but it seems to be cheaper going south which is 40 miles away from my husbands duty station and traffic is terrible.... please HELP! Pros and cons of purchasing a house... do you think we should wait? DILEMMA...DILEMMA