Sounds like the perfect use case for some sort of Orbital Express service, delivering (say) 10kg to LEO for a flat $250,000. That should be plenty, for a space capsule window repair kit.
Unfortunately, the economies of scale for an OrbEx just aren't there yet.
A human rated vehicle would be much more expensive than one rated for cargo. And there are not many use cases for the vehicle other than rescue missions to the two space stations.
I was proposing a drone-style delivery, of a small repair kit, for the damaged window on the Chinese spacecraft that is currently docked at their Tiangong space station.
Their astronauts don't need rescue. Nor a human delivery driver to chat with.
If a "10kg to (& from?) LEO for $250,000 flat rate" OrbEx service existed, 99% of the initial use cases would be launching cubesats. After a while, some LEO satellites might be designed to use it for additional reaction mass and other stuff. Space stations could use it for time-sensitive scientific supplies and zero-g manufacturing specimens, and an occasional priority repair part.
I don't think the repair could be done. It's not about plugging a hole in space. It's about surviving reentry. They can't guarantee the integrity of the glass. Anyway to your point they could stock the kits in space on regular supply missions, which again diminishes the utility of express delivery.
Unfortunately, the economies of scale for an OrbEx just aren't there yet.