Game publishers could follow the example of books. They used to price discriminate based on time, with ebooks they had to rethink their strategy. $15-$35 for downloadable-only, $50-$70 for downloadable + physical games, maybe even higher for collector editions, would probably work well.
I'm not sure. Games publishers have been at this for many years yet, they've experimented with price points, different forms of DRM and various online strategies.
I don't think there's any real evidence that cutting price affects price in any major way. Entertainment products are fairly price-inelastic* and collectors' editions are almost Veblen goods.
*Although they obviously respond well to sales and temporary price drops, permanent price cuts don't seem to help much.
