At time of writing theres about 10 hours left to nab this double pack which contains Supreme Commander and Alliance standalone. It's on a grander scale than Supreme commander 2 in many ways and very good. As far as I'm aware this is a digital download edition. I've seen it floating around for around £6.50-£9.99 lately.
Supreme Commander Gold Edition (PC) - £3.40 @ GamersGate (Until 7am on 19th April)