You can build an extremely similar bass for a little less money than an S2 model if your start with an MK Deluxe (comes std with coco bolo but CB is extra on an S2) and add all the other features as upgrades and you get the right monthly special.
The remaining difference between the MK and an S2 with the same appointments (literally, the same) would be the number of laminates used in the body. The MK Deluxe has 5 body laminates, the S2 has 7. See Malthumb's thread on his MK/S2
http://club.alembic.com/Images/411/460.html?1054003279 . BTW, a MK Deluxe can be made with a chambered body like an S2.
Apart from the body laminates, on the custom quoter, I get the base S2 in cocobolo to be $14K retail, while the Frankenstein MK Deluxe with S2 electronics and all those upgrades seems to run $13,250 retail. That's when the monthly specials really begin to matter.
The number of body lams was not important to me (who says 5 is too few?!?) and there were a few other options I knew I didn't want to spend for (i.e. gold plating, wood backplates). So I ordered my new bass as an MK Deluxe with S2 electronics and the upgrades I considered important.
Also, it can't go without mentioning: I'm still stunned at how helpful and willing to take time, Mica, Susan and Val were in helping me get as much possible of what was important to me for the best possible price. Thanks, again guys!! They'll do that to form a great relationship with a customer. But do them a favor: Do your homework first! That means spending a few hours digging information out of the Custom Quote Generator, the Alembic site and Club discussions on the options you may want. That will reduce the number of questions you have considerably and leave much more time with them to get creative.
(Lather, rinse, repeat, chill and serve)
Bill