Being that Summoner Wars is pretty much universally still in print, I'd just hop over to coolstuffinc, drop everything that you'd be getting into a cart and use that number as a baseline for value and adjust for condition. It's how I generally value stuff that is still widely available.
That may be a little high. As someone who has been trying to sell my SW collection, the prices folks are willing to pay for a large lot seem low. But maybe I've been unlucky...