Double-winged is always damn expensive. At one of the shops (fensterversand) you can see during configuration which little click (e.g. the one on double-winged) drives the price up, as it changes in real time. Fixed glazing is best.... then the burglary protection is also right, if you don’t necessarily need to be able to open it. Tilt-and-turn costs a lot extra again. I once looked for the laundry room, which is only 7 sqm, and for ventilation it’s enough for me to leave the door (briefly) open while I’m inside. That might be worth considering.