Just found out about the Bose Outlet store which sells refurb and open-box headphones with full Bose warranty. QC35 series II normally go for at least $30 more than this based on past Ozbargain deals.
Since Bose warranty and out-of-warranty repair only replaces headphones with new ones, as they say headphones are unserviceable, I'm not really sure how 'refurb' these could possibly be. I'm guessing they're ex-demo headphones or something?
They also have SoundSport Free wireless headphones — Refurbished for $179.95 (RRP $299.95, cheapest price I found with a quick search was $248 at Addicted to Audio)
For me, overpriced for used/refurbished.
For $30 more you can get them new from Amazon.