2616.com was left to expire and it closed at GoDaddy auctions at $58,000. This is the highest price for an NNNN.com reported in 2021. There have only been 19 reported transactions. Interestingly 14 have been at GoDaddy and I would guess most if not all were left to expire there.
The average price for an NNNN.com according to Namebio in 2021 is $18,900 compare that to five years ago in 2016 when the average price was $28,100.