Yes, Intel is the master of market segmentation here.  I don't believe for
a second that most of their best features just happen to have a high defect
rate that warrants setting the kill bit on all the cheaper badges slapped
on the common die.

A few years ago, I got a killer deal from AMD.  The Phenom II X2 555 BE.
In the right motherboard, it would happily attempt to turn the two missing
cores back on.  If successful, you had a Phenom II X4 955 BE.  And so I
did.  It's still a pretty nice beast - shame it's locked away in storage
for the moment.

Intel doesn't allow such nice tricks.  They'd lose too much money from it.

- Jonathan Morton