A window you can repair with a screwdriver is worth two you have to replace.
The cheapest window in the tender is rarely the cheapest window in the building. We added up three of ours, from the day they were fitted to the day they will be replaced.
At Schulhaus Erlen the window schedule was the third largest item in the budget, after the frame and the ground works. The town asked, reasonably, why we had specified solid larch when a composite section cost a fifth less on the day.
So we wrote it down. Purchase, fitting, repainting, new seals, one replacement of the glass, and the scaffold each of those needs. Over fifty years the larch window cost less, mainly because every part of it can be taken out and put back by one carpenter.
The composite window had no line for repair at all. When the seal fails, the whole unit goes. That is not a fault of the product, it is how it is made, and it belongs in the comparison.
We now hand every client the same one-page table at the end of the design stage. It has three columns and it changes more decisions than any rendering we have made.