If Stardock were to sell the same game cheaper on its website, no one would want to do business with them in the future. As a company, you can't sell to wholesalers and then turn around and sell the same game cheaper.
how would you feel if you had a really great tech to trade, expecting to get a lot from each Civilization for it but the first one you trade it to practically GIVES it away to everyone. You'd wanna kick their butts (if that particular race has a butt that is).
Some stores may lower their prices, even to the point of having a very small profit if it means attracting a new buyer-for-life and if it means getting you to their store to buy other things while you're there. Pehaps you'll want to upgrade your graphics card, get better speakers or buy a second game. So you can't always look at what the stores are doing. Super markets do it all the time with life's staples, milk, eggs etc just to get you into the store so you'll buy their overpriced Oreos.