I think that might be a very misleading way to think about it. Sure, maybe Apple could buy 12 nuclear carriers (Although I think inflation may have changed that number a bit. [Also, your $6.2 billion figure is apparently sourced from Fox News[1][2][3], which (of course) doesn't cite a direct source for that claim, only an author credit to Associated Press[4]]), but assuming they did, all they have is 12 huge hunks of metal that they need to store somewhere.
Oh, were you thinking of a fleet of operational carriers that can deploy world-wide dozens of the most highly armed and agile vehicles within 14 days?
Maybe you were just thinking of putting those carriers out on display in the southern bay? I don't know, maybe.
But, if you were thinking about the (apparent) price paid for what the US actually bought (what your numbers are supposedly based on), you need to include the ongoing costs for operating and maintaining such a fleet. According to your sources (Wikipedia), the US Navy had a $171.x billion budget in 2010[5][6][7][8] (according to the same source, this is now $147.69 billion for 2015). I zoomed around the infographic more and found that Operations & Maintenance run $40.xxx billion this year. Sure, you can drop it down some to get rid of the non-carrier vessel maintenance, but this is the limit of the graphics breakdown of the budget. There's another $3x.xxx billion in there (pan north a bit) for "personnel" costs. We'll be generous and say that[$7x.xxx billion]'s an upper limit on the annual cost to run the carriers as you are likely imaging. If Apple keeps it up, they will be able to pay for the first year's costs before next quarter's earnings.
[1] http://en.wikipedia.org/wiki/USS_George_H.W._Bush_(CVN-77)#c...
[2] http://www.webcitation.org/6DBeItQye
[3] http://www.foxnews.com/story/2009/01/10/aircraft-carrier-nam...
[4] http://www.ap.org
[5] http://en.wikipedia.org/wiki/United_States_Armed_Forces#cite...
[6] http://www.wallstats.com/deathandtaxes/
[7] http://www.timeplots.com/
[8] http://www.timeplots.com/collections/catalog/products/death-...