perferably under denver airport or in a abandoned missle silo
A basic one would be about $1,000,000.00 and a luxurious one could double that price easily. It's going to be very hard to do it without any government connections. There is always red tape and permits to go with every construction site. I hope you win a big lottery and all the best to you with the local bureaucrats.
They Start at a Million, Silos116!538:538 go (straight) up- from There. -If you're lucky, the Owner will throw in the Missile- for free ! ;)
The real question is: Would you really want to? This is one of those If you have to ask, you probably can't afford it kind of things. Anything you build would have limited resources to last for very long, i.e. clean water, food, power, etc.. So you have to HOPE that whatever disaster you are trying to ride out isn't so bad that you emerge only days, weeks or at best a few months later into a destroyed world with NO CHANCE of continuing to survive. The next question then becomes, if the disaster you are avoiding is not epic in the scale of the 2012 movie, you could likely survive above ground if you play your cards right anyway.. Look at Haiti from yesterday. Thousands and thousands may have died, but many thousands more will have survived. With all of the damage, resources will not be available locally for months or possibly years in some areas, so they will come from other countries. IF this destruction was planetary, there would be NO replacing those resources before most will starve to death. Those that died almost instantly rather than a lingering, slow death by starvation might actually be the lucky ones. So, just because you could, would you really want to?
