not impressed
to get 7xmg its costing me $43 aud!!!!!!!!!!
Sorry to sound rude by the ppl who said its cheaper to buy it. are full of crap and don't live in Australia. here we have to sacrifice our money as well as our arms to by anything!!!
What would it cost to mine 7 xmg?
With current blockreward mining at 300 KHs will do 2.55 xmg per week.
So almost 3 weeks = 3 weeks * 7 days * 24 hrs = 504 hours of mining.
abt 65 Watt of power for a dual xeon processor.
504 hrs mining * 65 Watt power = 32.760 Wh (Watt Hour) = 32 kWh
In the Netherlands 1 kWh cost abt 0.22
So this example would be abt 7.30 to mine 7 XMG
if you can make it to 300 KH/s and have a cheap power consumption on your CPU. This is excluding other costs like the power of your PC RIG and setup costs of your PC server
If your CPU is draining way more power then this, just see what 130 Watt of power will cost (twice the amount)
Now take a realistic power consumption for this setup, is abt 390 Watt per hr. 
Almost 200 kWh * 0.22 euro = 43 euro for 7 XMG
Simple math?!?