I recently got an S5 and am hoping for a nice case for Christmas. I needed something to tide me over until then so bought the cheapest I could find on Amazon. It's actually a really nice piece of kit and does the job really well.
Strangely, for something so cheap, it's not an Add-on item. I paid my £1.79 and it came the next day with Prime, otherwise I guess you wait a couple of days for Super Saver.