Count me in! underground bunkers are not uncommon. We've had several pass though our survival property listings in the past few months including DIY bunkers. http://survivalist.com/property/

Here are a few more resource links if your serious about finding a Bunker or Building one:
http://www.missilebases.com/
http://www.atlassurvivalshelters.com/
http://www.risingsbunkers.com/
http://www.ultimatebunker.com/bunker-pricing-floor-plans/