Amazon currently has Steamworld Dig 2 (PS4) for $12.08. Price has been fluctuating for the last few weeks but is currently in a downward trend.
It's kind of a no-brainer at that price because its a physical disc that you can resell if need be, and its much cheaper than the regular $19.99 PSN price.
Metacritic score is also excellent at 85 currently.
Switch version is a bit more at $26.19: