Humble Bundle offers Steam downloads of the Humble Bundle Sci-Fi Edition for Windows for whatever you want to pay. If you opt to pay the bare minimum of $1, you'll get Velocity Ultra, Cosmic DJ, and Q.U.B.E.. That's the lowest price we could find by $15 for these games purchased separately elsewhere.
If you opt to pay $6 or more, you'll get The Fall, Strike Suit Infinity, and Strike Vector. Finally, pay $15 or more to get The Last Federation. Deal ends August 7.