Steam now lets you gift 'complete the set' bundles to your pals, including relevant discounts

These days, the only time I recapture the sheer rush of Steam sales of olde ("I can buy every Quake game for £5? I'd be a fool not to!") is when I find one of those 'complete your collection' sets some games have.

You know the ones: they combine a bunch of games in a series, subtract the prices of the ones you already own, then slap a little discount on the remainder to tempt you into splashing out to complete the set. When you find one of those in the midst of an already-ongoing sale, making it all even cheaper?