Well after seeing it in action I'm really looking forward to the production kit for my newly acquired black hawk 2K X. Some of my pixs can be viewed at:
http://www.xterraownersclub.com/ubb/ultimatebb.php?ubb=get_topic;f=36;t=001710

Since costs seem to be a hot topic, for my stock X I'm planning on running lockers on both axles, 5.14 gears, 35" tires and my ballpark budgeting so far:

Core Parts:
$2.5K for the kit (~ about the same as a Jeep TJ long arm kit's)
$650 for a used D44 front 80's waggy axle ($325) refurbished with some new brakes parts ($125), lines ($50), ball joints ($50), wheel bearings ($50),misc ($50).
$250 front R&P gears, new carrier, master install kit.
$350 used rear 5.14 gears/3rd member (possible to avoid this w/ stock rear 4.9's)
$400 front CV drive shaft

Core Labor:
$350 Rear lockers and R&P install/setup. The no slip is a lunch box so I can install that myself.

$4500 swap subtotal including the kit, axle, gears, misc

Options:
$150 HD front U-joints
$225 Used D44 power trax no slip locker
$700 Rear ARB locker
$300 Skid plates
$850 35" tires and new rims

$6725 with lockers, skids, new tires, misc

Options I'm likely to take in the future:
$250 Rear Slip Yoke eliminator
$300 Rear drive shaft
$1250 3.9 crawler gears

$8525 eventual grand total

I'm planning on doing most of the work myself expect the gears/lockers with the help from friends when it comes to welding of the front arms and grinding that's needed. I confident that the whole swap can be done over a weekend

The thing about a SAS is one thing leads to another for me at least and I'm sure I will most likely end up doing more than I planned like a cage or something. Sure you can do the basic swap for less then my est. budget but for me I don't see the point of a SAS without lockers or some of the other goodies/options. Hope my estimate is high but I'm realistic and been through a SAS once already.

BTW my 2k Black hawk X is going to be my 2nd Nissan SAS , my 90 Pathy was my first and it wheels great but not really suitable as a DD but was lot less expensive (including the truck and all the mods < 5k) for a leaf sprung setup. I saved some by buying used, bartering, on closeouts, etc. and plan on doing that this time as well

Brian