Bitmain wouldn't sell the S4 at $1450 if BTC value was much higher. It'd still be much higher than it's competitors are charging, and history proves this.
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For comparison only 1 competitor:
SpondooliesTech SP20 price and shipping cost. $1,190.00+$160 (EU) +$119 (US) second half of October and no PSU only 1,7TH/s
Which one is cheaper?