Listed in their weekly ad:
https://www.frys.com/ads/page121
Was $399
Instant Savings $50
$349 after savings
GameStop also lists it for $349 in their Xbox Sale: https://www.gamestop.co
Perhaps Microsoft will announce the new price Sunday – as the prices are not live in cart yet. The E3 promo is supposed to be $50 off, so maybe the $399.99 price is the new MSRP, and the $50 E3 discount brings it to $349