The op is long gone and this was a 2015 thread.
But with eth coin gpu mining now can make money again.
There is a lot in favor of gpu alt coin mining if you game and have a gaming machine you will discount your gear.
If you build a rig correctly it can last for years .
My ltc rig sat on a shelf for more then 18 months. I finally got around to firing it up and mining eth coin.
Cost was zero. Now the rig is earning money every day.
Do I think I should build a lot more rigs no I do not but I will run this until it no longer earns a profit then shelf it.
The problem with shelving it was you put nice video cards on a shelf for 18 months, that means they lost value sitting there as new generations of GPU's come out. And they do always keep coming out with new GPU's.
I personally am more likely to sell GPU's (which I did on almost all my rigs) and buy back in if I want. ETH has a lot of fan's but has not convinced me to build any new rigs/buy back GPU's. And I could be missing a big opportunity... but I have a hard time shelling out for GPU's at current point. I would need to see long term gains personally.