Affordable DIY iPhone 4s screen repair?

I fell victim to the cracked iPhone 4s screen epidemic. I've had many strangers in public tell me they've repaired their screens themselves with kits they bought online for about $10, but I can't seem to find a kit under $50. Anybody know of the least expensive/most legitimate way to go about fixing my screen?

Link to Amazon: http://www.amazon.com/...zon.com/s/

Read the reviews before deciding.