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.
I have it at 475kh/s, and it's using around 180w. It's a really good card, but instead, you really should get some gridseeds, since they use a lot less power than GPUs.
I considered pickig up some Gridseed units not long ago...had a deal lined up even (2+ Mh/s/$500 shipped) but then I thought about it and realized the R9 270 a better deal than ANY Gridseed as once mining is no longer profitable a Gridseed will become a paperweight...a GPU can be sold as a gaming/workstation video card afterwards.
Correct, but a Gridseed also comsumes much less power than a GPU. Where do you buy your gridseeds from?
True. I've got a 3x 270 mining rig and it barely costs $1/day but is pulling in over $3/day in profits. When I can no longer make a profit mining with my GPU's I can build a couple systems and sell those or just sell the cards alone.
I found a deal on some modded Gridseeds not long ago (here on the forums) but decided on another S1 plus another R9 270 instead of the Gridseeds. An S1 will be profitable to mine with for at least a couple more difficulty changes as they can be undervolted for improved efficiency. I've been considering overclocking my S1 units at least until either next difficulty change or the hottest weather, not sure though as they are still under warranty.
Modding a Gridseed is a pretty simple process and if I invested in any Gridseeds I would consider used, pre-modded units, depending price, otherwise I would rather buy new and make the mod myself.