Best selling is a stretch. According to comichron list, he was around the 100th position in January 2020. If that is not good by today's standards, it was not good back in 2020 either, Especially for a respectable seller like Nightwing. He started to dip into the 18.000 units sold and i think that is a all-time low, not 100% sure tho.
He was still selling more than Aquaman, Batgirl and Teen Titans tho, which is insane that this franchises got to that point.
https://www.comichron.com/monthlycom...0/2020-01.html
When i was writing my post, i didn't saw yours. But, yes, that is correct.