at a certain point shutting down the mines will be neccesarry.
$436 and falling
If you're mining to turn a profit, maybe.
I'm more interested in just making a slow and steady conversion, since my computers are always on, from dollars into the electric bill to BTC. Will I ever need them? Maybe, maybe not. TigerDirect takes them, and so does my preferred site for MP3's, so there's that.
That being said - 2 new Antminers fired up today, they'd already hashed more shares in the 5 minutes they were on than my GPU had in what was the 90 minute lifetime of the chrrent block so far. Yay.