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Looks like an XCom Weekend Sale was added at GamersGate / GamersGate UK.
XCOM: Enemy Unknown = $19.98 / £11.98 (Steamworks)
X-Com Terror from the Deep = $3.00 / £1.48
X-Com Enforcer = $2.98 / £1.48
X-Com Apocalypse = $2.98 / £1.48
X-Com UFO Defence = $2.98 / £1.48
X-Com Complete Pack = $7.48 / £4.98