Prey (PC Digital Download) $6.15 & Prey: Mooncrash DLC $3.50

AllYouPlay.com has Prey for PC Digital Download on sale for $6.83 – 10% off when you apply promo code GGDEALS at checkout = $6.15
Green Man Gaming also has Prey for PC Digital Download on sale for $6.30
Voidu has Prey: Mooncrash DLC on sale for $4.16 – 30% off when you apply promo code FLASHSALE30 at checkout = $3.50