Scrypt-Based Mining now is just generally dead. I don't see the point anymore, even if you have Mh/s, you're still losing a LOT with electricity costs.
Some people have access to really cheap or even free electricity.
True, however my single card rig (303KH/s) uses 240W solid when mining. I have it on for 9 hours each day during the night since mining scrypt is so unprofitable ~ at least for me anyway. Its around £9 a month now that I'm doing this minus a couple pound due to my solar panels which are grid tied.
Pick up an R9 270 yo! Coupled with a Sempron 145 you can have a low power single rig pushing 430+ Kh/s and fairly low temps...should be under 175w! Also GOLD rated PSU or better helps a bunch.