"Officially, Congress must make a decision on the ISS by 2024, when its funding expires. But beyond routine maintenance and the occasional orbital boost, the station needs no major repairs. "As it happens, some stuff is functioning vastly better than imagined," says Keith Cowing, editor of NasaWatch (a NASA watchdog), who helped design the station as a NASA employee in the 1990s. "Maintenance is little things like replacing batteries when they die or tightening valves when they need it."
... Even with a government-mandated nonprofit charged specifically with ginning up business, nobody has found a killer app for low Earth orbit. Yet. Cowing sympathizes with NASA's funding plight, and says it shouldn't indefinitely tie up resources on a mission barely beyond the stratosphere. But he doesn't think that should seal ISS's fate. "NASA has spent decades building and operating this thing, has gotten it just to the point where it can actually start doing things, and all of a sudden you want to scrap it all and start building something else," he says. What a waste.
... Plus, buying it lets you do whatever the hell you want. "I like to refer to the ISS as the Undiscovered Country, both in the Shakespearean and Star Trek-ian sense," says Cowing. "It's completely underutilized."