You provide absolutely no source for the cost assumptions. Also, private, individual vehicular traffic is not a GDP generating parameter.
And no one is saying there should be a fee for street parking, but rather pointing out that we're all subsidizing stretches of public road for private use, and that this should not be something that guides urban design principles. Bike lanes benefit a substantially larger amount of individuals than subsidized, "free" private parking for people in front of their homes. Again, you want a guaranteed parking spot right by your front door? BUILD A GARAGE OR A DRIVEWAY. Otherwise, the general public benefit far outweights private needs, from a city planning standpoint.