How many euro do I currently get for these Nintendo things?

Dinosaur King (DS)

Pirates of the Caribian (DS)

Mario & Sonic at the Olympic Winter Games (DS)

Doom (GBA without packaging, with instructions)

NES Classic Super Mario Bros. (GBA without packaging)

Star Wars (GBA without packaging)

Dr. Mario + Puzzle League (GBA without packaging)

Island Xtreme Stunts (GBA without packaging)

Mario & Donkey Kong (GBA without packaging)

Animal Crossing New Leaf (3DS)

Super Mario Bros (3DS)

Super Mario Maker (3DS)

Mario & Luigi Dream Team Bros (3DS)

Mario Kart 7 (3DS)

Kirby Battle Royale (3DS)

Donkey Kong Country (3DS)

Mario Tennis Open (3DS)

The Legend of Zelda Ocarina of Time 3D (3DS)

Yo-Kai Watch (3DS)

W2C Fifa World Rally Championship (3DS)

Animal Crossing Happy Home Designer (3DS)

Luigis Mansion 2 (3DS)

Zelda Majoras Mask (3DS, without packaging and instructions)

Mario & Sonic at the Olympic Games 2012 (3DS)

Fire Emblem Shadow of Valentia Echoes (3DS)

Ninjago Nindroids (3DS)

Code Name Steam (3DS)

Dinosaur 3D (3DS)

Tomodachi Life (3DS)

Rayman Origins (3DS, instructions damaged)

New Nintendo 3DS charging station (with packaging)

Cover for 2DS

Case for 64 Nintendo games (3DS)

New Nintendo 3DS (with two pairs of decorative panels)

3x charging cables 3DS (2x original, 1x to USB)

Gameboy Advance SP (slight scratches in the display, you can see in bright light if you sit at the wrong angle, housing has many scratches)

1x original charging cable Gameboy Advance SP

1x KK Amibo figure (guitar broken off at the front)

1x Björn Amibo figure

1x Moritz Amibo figure

1x all AR cards (packaging damaged, 3DS)

Age-related signs of wear

Everything works fine.

You can't set a fixed price for everything, everything is extremely old, nostalgia hits for collectors / fans are not really included, which one could possibly have sold individually, since the list is a pretty mixed bag. The only asterisk in the list is the Gameboy Advance. SP, that is still a very popular device today… You could have asked for something for that, together with the matching games, but the condition doesn't seem to be the best any more, compare the prices on ebay classifieds and think about it good offer. The GBA games like NES Classic Super Mario Bros are also extremely popular (nostalgia).

I would group things together, do everything from the 3DS together, everything from the GBA together, etc., so everything that belongs to each other and then sell it that way. You will most likely not get it all at once in private, but if you want to sell it in the store, that's something else again… I don't recommend it though, as more and more money is lost.

Just compare the private market prices online (ebay classifieds for example) and see what others are asking for, depending on which you then create your own offers.

Thanks first for the answer! I'll just put everything in once, another display Gameboy Advance SP, the other 3DS / DS and then another one especially for Super Mario Bros Nes Classic

Animal Crossing and super mario can always be sold individually. This is generally popular and does not need a collector to come. Just compare the prices on different pages.