THis is how its computed:

BTC price during ICO : $ 630.00
ETH Price during ICO : $ 10.837
Initial 5M offer : 700 NXC/ETH
Final  5M offer : 425 NXC/ETH

@Initial
10.837/700 = 0.01548142 USD/NXC
0.01548142/630= 0.00002457 BTC/NXC

@Final
10.837/425 = 0.02549882 USD/NXC
0.02549882/630 = 0.00004047 BTC/NXC

Look at where it is now. You know what they say when Coins fell Below ICO price. I dont have to spell it out.
http://beyond-the-void.net/index.php/nexium-price/