Next to nothing.
But we are gaining invaluable experience on how to build, live and work in space. Hopefully, some day the space station will one day become a
facility useful for many other purposes, like manufacturing or science or a spaceport and shipyard facility.
But, I have a feeling criteria like that were never part of the initial design, and it's unlikely the finished product will be optimized for any single useful purpose, or adaptable enough to be used for a variety of purposes. In other words, it will be abandoned as too expensive and impractical to operate.