Nation Z and Nation W are both researching some common issues. Those working for Nation Z get a double helping of pudding for their family for each patentable discovery they make. Those working for Nation W get the patent rights. Nation Z researchers might want to pass a few things through the hatch for a cut of the cash. This doesn't only apply to Nations, but to the companies represented within.
Success runs rampant.
Not only are a the big companies back home getting rich, but a few hackers have found gold in zero G. Somebody gets the cash together to buy a module or two, and a new station starts to develop. A new station that charges rent, but has declared itself a sovereign nation that doesn't have an income tax-or it's registered in Iberia. Russia goes back to communism and takes their rockets with them, or a Shuttle crashes and we ground the fleet for a few more years, or some of the countries run out of cash and pull out, or something else happens and it just doesn't get built. .