I'm not mobility, so someone else may know better than I would.
I have a friend at work who broke his s3 screen. Samsung told him approx 300 for them to repair.
He fixed his with a kit he bought online via ebay for 20 bucks and a heat gun. Although the DIY fix worked, it wasn't perfect and he described a slight haze on the display afterward. So although inexpensive, it's not guaranteed to be a high quality repair.
Did you get the insurance( Device protection Plan) with your handset? If you did, you can get the device replaced for a 1 time charge of 150.00 through handset insurance. You would have had to purchase handset insurance when purchasing the device.