If you edit your contacts (via Gmail or on your phone) you'll notice there is no concept of First and Last name. How they are sorted depends on how they are input or imported.
I personally wouldn't consider it worth the money just for name order, but I don't know how much it bothers you--I use CompanionLink for USB sync, and it does give you the option of displaying names last name first on the Droid...just a check box, a sync, and it's done. You can always get the 30 day free trial, sync the contacts once, make a point of not making any new friends.