The 4930k tray pricing is $583 (The jump to $999 was too big.)
The 4820K tray is $323.
$130 more per core and 1.5mb increased cache.
The motherboards are about $500 vs the $200 range for the 1155 boards.
I think everything else is priced the same.
You have done the analysis and can summarize but it appears that going 2011, over 1155 is accepting the increased motherboard cost. About $300 and I expect will shrink as part matures.
Going with the beefier CPU is a pure adder after you decide to go 2011.
It appears that the CPU choice is more varied than I thought. I thought the Extreme parts were all at $999.