Even though Apple suggests Mac users without Leopard buy the $229 Mac box set to get Snow Leopard, anyone can purchase the $39 Snow Leopard disc and install Snow Leopard in its entirety without having already installed Leopard.
This means the Snow Leopard DVD isn't an "upgrade" at all; it's the full-on Mac OS X operating system for 40 bucks. (Something we missed yesterday when we told you how to prep your mac for Snow Leopard.)
I suspected this was the case, since it is with the developer build I'm running, but The Wall Street Journal's Walt Mossberg confirms it's true for the final release as well
So if you're jumping from Tiger to Snow Leopard, you saved never purchasing Leopard and you can save skipping the box set. Guess being a late adopter does pay off.