Living in the home of the DE warmbloods, it depends entirely on what you want to use them for.
Mares still have to prove themselves, and will be establised as your general mare 'Hauptstutebuch' or 'Stadtstutebuch' or 'Silberpramiertestutebuch' in that order, not heard of anything higher than silver, but that's the order they go in. After that is established, anything over 7,5 is notable, but for crem da le crem you look for 9+.
For geldings, they have to prove themselves from age 3-3,5 up as sports horses. If they don't make the 'prufung' as a sports horse, you'll go for less than €6,000. Over that, and it depends on what level, but with those lines I wouldn't go over €6,000 as a 4yo broken in as you still get a lot of 'direkt' from Donnerhall, Donnerschlag, Fisherman's Friend, Weltmeyer, Cassini, Gotthard, Rubenstein to name just a few.
View 'Abstammung' for breeding lines
Hengstfohlen Hannoveraner Dressur Dressurnachwuchs W-Linie Wolkenstein Lauries Crusador xx Auf dem Weg in eine erfolgreiche Zukunft 4yo mare broken in already