Great, Thanks for your help! I think I'll shoot for the S5's then.
Head's to eBay
It's not a bad option. I would do some ROI math first though. As free electricity S3 might get you more power for your buck. Or A1's like I mentioned.
S5 is still not bad of efficiency so you will pay more then older tech. But with free electricity sometimes it's not needed on new tech.