$4,000 to $5,000 with you pulling the engine and delivering it to a mechanic.
The sky's the limit if you have the engine pulled. Remember, you've got to remove the bonnet, tear down the front end of the engine (pullies, water pump), jack up the rear of the car, and hoist the engine and trans out as a unit. Believe me, I know!
You can save money by doing it yourself, but take it from someone who's rebuilt pushrod English engines, the double overhead cam Jag engine is vastly more complex. You've got to get the cams installed and synchronized and from what I've seen, that takes an experienced hand. The machine shop (if you find the right one) can set up the valves: but again, they don't have adjustors like a pushrod engine, they have small disks that determine valve opening (and you have to choose the correct disk for each valve)
There are also some "tricks of the trade" out there that are good to know. My engine got a new front crank seal and collar made of silicone and teflon, with an o ring inside the collar. Very neat, hopefully no front seal leaks.
Again, despite my comments, I love the thing. Also, I've been quoted $3,000 for a full TR6 rebuild, so actually the cost for the Jag doesn't seem so outrageous.
Steve