Think again. $40k gets you 5 TH delivered next week. By the time you get the Neptunes, difficulty will be much higher. 5 TH now is far more profitable than 12 TH several months from now.
5th next week? Who sells them?
25+ Antminers from Bitmain.
https://www.bitmaintech.com/product.htm3th of Antminers = 5kw (by taking 300watts per Antminer) = 31.654
BTC (without shipping) = 25.8k $
3th of Neptunes = 2.5kw = 14.6
BTC = 12k $
Two times more $$$ and watts for the same hash-power.
Don't forget to discount antminers with profits they will make until Neptune is in your hands.