Energy cost? These devices are pretty efficient, my Mi Router 3G uses 3-4 W and this with J3160 CPU uses 6-7 W, yes I did measure. That's just a difference of 2 units in a month, even at a high electricity rate, translates to a difference of Rs 15 or so in a month.In the long-run energy costs would add up(J1900 is a great chip with aes-ni support if you want to save some electricity cost).
Haha awesome. Now another 1k in customs duty!