I had the ND mid-size added for about $10/club when I ordered my set.  Basically same price as I could buy them for retail but I didn't have to mess with getting them put on or doing it myself.

depending on where you purchase the clubs, I've seen the up charge as low as $4 and as high as $7.  If you find a local shop though, many times they will throw the grip upgrade in with the purchase of the set of clubs. Either way, the upgrade and payment is well worth it. I look at it this way, if you're already spending $1000 for clubs, does it really matter to spend a few bucks more for a better--desired grip?

good luck to you!