Of course the price of the console isn't everything but I think it's certainly a key component when launching a console. The cost is especially important when the competition is stiff with PS4, PS4 Pro, and now the Switch on the market.
The Xbox One S sells for MSRP $300 USD but often found for $250 or lower on the regular for a reference. It should be noted that the XB1 isn't doing bad whatever the perception may be. While the PS4 is breaking records and have the potential to become the best selling console of all time, XB1 is actually slightly ahead of the 360 when comparing the 1st three years of their life.