I don't believe that the FF sensors cost dramatically more to make than 1.6 crop sensors. They use the difference to allow them to sell cameras at a lower price point to 95% of the people buying cameras without undercutting the prices on their own FF models.
You would believe wrong then.
A FF sensor has approximately 2.6x the surface area, so they only get about 1/3 as many on a wafer.
Because of the increased surface area there is an increased risk of flaws, but not a 2.6x increase, a 6.9x increase. (actually 6.9x (square of the difference) sounds a little high, so don't quote me on that. I do know it's not linear though.)
There is also the reduced volumes vs. APS-C, especially taking into account for the 18MP sensor that has made it into seemingly half the APS-C bearing line.
Add those all together, and you get massive cost increases.
As to your second point (unquoted for brevity)...
Even an APS-C sensor is larger (up to 2x) than the latest 6 & 8 core Intel processors. Have you priced out an 8 core Xeon lately? They start north of $1k in bulk. And even the newest 10 core E7 processors are almost half the size of a FF sensor, and they start at about $2500.
Sensor vs. CPU isn't an entirely fair comparison though. Processors are several orders of magnitude more complicated, and expensive to fab. They're also more sensitive to flaws.
So I guess my takeaway point is... Things are more complicated than you think.
You quote the retail price of Intel CPU's, which misses my point. Whatever the retail, you know it doesn't cost Intel anything like that much to produce. Even if you can really translate surface area directly into fab cost (cost per square centimeter), and the surface area is 2.6 times greater, and even if the 0.05% dud rate is really multiplied by 6.9x or whatever number you toss at it, I still am not convinced that the actual cost to make it is that great. 2.6 times what??
The dud rate is WAY higher than that, considering it's not intel making these, or any other company with state of the art fab, for that matter. Just did a quick check and Intel's Ivy Bridge processors are about 5-8 times smaller than a full frame sensor, so square that and then add cost due to a less optimized process and let me know how much you think that costs. These things are NOT cheap, despite how much we want them to be. Until we agree to accept a smaller sensor, they won't be cheap.