I was using "X" as a chance. This chance is actually higher, because not all people with Nxt are forging, forging are maybe 1%, so chance can be 0.0001. But still, with this number, if you use 100x 1000 Nxt, you get chance to: 0.01.
But if you had chance 0.0001 with 1000$ GPU for BTC, you would have chance  0.01 with 100x1000$ GPU (+100x electrocity), but instead of buying 100x1000$ GPU, you would buy 1 supermachine for 100.000$ and the chance wouldn't be 0.01, but 1 or even more. Bitcoin is rich get richer.