The parts cost is something like $60 or less if you get new hardware. A new spindle, 61628220831, adds another $70 to that. Mine was good enough so I did not buy a replacement.
I received the parts last week but work and yard work have keep me busy so I have not installed them yet. The 61319200673 button comes with a rubber gasket. Also, the design has changed. There is no longer an exposed center pot metal sleeve. It looks like the plastic is overmolded to cover it. This is an improvement because the metal center sleeve was badly corroded to the wiper spindle in my car.