calculating an 4th miner put in function 2 months ago is ~600$
http://www.newegg.com/Product/Product.aspx?Item=N82E16817377050
To get 4TH we talking a lot more power and standard home outlets don't allow over 1800w so unless this is JUST for data centers we won't see a 2kw home miner s6.
2x 1200 watt server psu's = 2400 watts easy peasy
.4 watts a gh = 6000gh done if they want to do it.
Plenty of home miners could run that. All you need is one 20A/240V outlet. Perhaps you mean "A home miner that is not willing to spend a dime upgrading their homes electrical system cannot run it."
I would not say no one. I am lucky to have 2 lines going to house and decent wiring. I was running 12430 watts approx during winter. That is well above 6T you mention.