But if you're curious re:prices, you can call the dealer listed on Controller.com as selling a 777. He's actually got several for sale in that neighborhood (and is super friendly, too - Eric).
On the cash front, ferry flights to the US are the biggest expense by far. A 777 burns ~$10,000 in fuel per hour, so positioning from (say) Asia to a boneyard in California adds up quickly... with crew, ferry insurance, landing fees & sundries you end up at $200-$250k. Parking runs around $3-5k per month in the desert, too.
I figure if you're starting at, say, $150k to ferry it, might as well fill it with some junk.
Incidentally though, the FAA minimum liability coverage for a widebody is $750 million, and the policies I've seen do allow for cargo onboard (though not passengers).
Ferry permits can be issued to airplanes “not airworthy and operating outside their certified range” if I am not mistaken.
Also, is it possible to buy non-airworthy ones and fix them up and sell them as air worthy ones? Or is it too expensive?