You may remember the news before about how Opera will be taking over as the main browser on the more entry level or “classic” Nokia handsets (not Lumias). This includes Nokias based on Series 40, Series 60, Symbian, Asha or Nokia X.
Along with this change is the closure of Nokia Store for Opera Mobile Store.
As mentioned in comments, paid apps in Nokia Store won’t be downloadable in Opera Store – if there are even equivalents.
Cheers Alvester for the tip!