S9J is 93 W/TH and still profitable at $0.10 kWh depending on pool fees. Anyone that doesn't care about current value/quick profit most likely only cares about $/TH to mine as much BTC as quick as possible with lowest initial investment. M10 is $54/TH and S9 w/PSU is $31/TH.
That's a 43% price increase for 27% increase in efficiency.
If these were priced inline with S9, not considering efficiency increase, it'd be $1,023 ($31*33 TH/s). Add 27% for efficiency increase and this should be priced at $1300.
At $1800, it seems like they are trying to recoup losses on M3 sales when Bitmain and Avalon price warred each other and they didn't follow. They were still trying to sell for $700 for the longest time when S9's were $500.
The s9j is 93 watts only in a cold room.
It is more like 95 in a 85f room and more like 97 in a hot room.
If you have 3 4 5 cent power you would be a moron to buy the m10 but at 10 cent power the m10 looks closer and at 12 cent power the m10 looks better.
Why buy an s9j if you have 10 cent power and a hot room it loses money now. Or makes a dime a day.
The m10 makes money at 10 cent power and will do so for months.
The s9j will certainly be the choice of a big guy with 3 4 5 cent power.
But a marginal miner with 10 cent or more power cost the m10 has an attractive feature it makes money now.