We have planned a similar scale of windows. Referring solely to the fixed glazing, I would also estimate around €50k. There are two influencing factors here, firstly the frame material. Furthermore, you will find it difficult to achieve a Uw value of <0.7 (if at all, probably only through higher financial expenditure). Ug is certainly not a problem, but for the entire window, that is quite ambitious. However, I am happy to be proven wrong here.