That price includes the valves. It's $11.50 for the bulkhead, then +$11 for a valve added. Also looks like the kits come with brass valves.
Oh, and 17lbs of grain would fill that 7gal to the brim. I just like the 10gal because, it leaves you plenty of room for pretty much any kind of beer you would ever want to make. I would never want to get a stuck mash in a completely full mash tun. Just my personal preference on the 10gal though. Homebrewing.org has some decent priced kits if you just feel better buying it all together from one place.