Sony Partner Store has the WH-1000XM6 listed for $419.97 delivered. Which is cheaper that what you can grab a WH-1000XM4 or WH-1000XM5 at the moment.
If you happen to also have the Sony AMEX Offer (Spend $350 or more, get $50 back) available on your card this brings the total price to $369.97.
It didn't occur to me at the time I purchased but if you have Cashrewards, if it works currently they have 12% Cashback until midnight tonight (30/05) which could bring this total price to $325.57 if it's applicable to this order.
Comes up as $699 for me