So according to that link, G-DAJC will operate the flight on May 15. If I got to book that May 15 flight on Condor's site, Economy is $379 and Premium Class is $549. For Premium Class, it lists various benefits like higher checked baggage weight limit, but also "Lots more legroom" which would imply they are indeed better seats.
Or maybe the details on Condor's site are incorrect, given the plane being used to operate the flight?