had a 10€ logitech for years, very good, very durable, nothing special.
Then I tried the G400 and I must say for me this mouse was terrible. Compared to the 10€ mouse the buttons were extremely loud and it felt like a5mm gap between buttons and mouse. Also the position of the buttons and the mouse itself felt completely uncomfortable and after a bit playing my fingers started to ache (I have rather long thin hands).
Then I tried the Roccat Savu (40€) and this mouse is perfect for me. Everything is tight and felt right from the beginning and it looks good, not too robot-like.