Bolded is exactly why 290(X)s weren't selling well even after the first price drop post 970(980). It wasn't selling, that's why they dropped prices. It took a name change and the corresponding reviews to ditch its launch reputation as having a terrible cooler by forcing, if they want the page hits that come with a new GPU release, tech sites to properly evaluate and tell their readers how custom cooled 290(390) performs.
Just pointing out your own conclusion shows "AMD could had easily sold the 290/x series at whatever it's competitors equivalent was but instead they sold it for far cheaper." isn't true. Imo, any price rise on remaining 290s will be mostly due to retailers finally reaching the end of their stockpile.