Those are sunk costs. It now costs an additional $1.3 billion per year to keep the Space Station operating. The parts were designed to last 30 years and some of the parts are now 32 years old.

Raising the space station to higher has technical risks, large costs and space impact risks. Deorbiting the space station at the end of its life is the safest and only viable method to decommission this historic symbol of science, technology, and collaboration. Saving the space station could easily cost $5-10 billion instead of the less than $1 billion to safely de-orbit. The Space Station that was saved would still need costly maintenance and it would not be designed for the new age of the SpaceX Starship. It would be far more valuable to start fresh with many new, bigger and better space stations for less cost.