请教：窗户

请问像这种窗，可以只换下面能滑动的部分吗（上半部分是不能滑动的）？

收到一个报价说要全换，一千多，合理吗? 谢谢！

-Remove the siding around window -Remove the full frame -Dispose of all debris  -Add new Vinyl MI window to match closest to existing. -Flash and tape things properly. -Re-install siding around windows on outside -Install new trim on the inside -Price includes all labor, materials and disposal.