Amazon.com has Escape From Planet Earth (3D Blu-ray + Blu-ray + DVD + Digital Copy + UltraViolet) on sale for $7.50. Shipping is free with Prime or if you spend $35 or more.
NOTE: This is temporarily out of stock but will ship when it becomes available. Check iMDB for reviews on this movie.
If you don’t have Amazon Prime, there’s a free 30-day trial with free 2-day shipping, video & music streaming and more available.