Uh... How you figure? Only the infrastructure needs to be paid for. The "switching fabric" if you will. And of course the power you use to run the computer.
It costs nothing else to put a packet out there on the Net sans doing so through a draconian metered connection, and surveillance capitalism had nothing to do with that. In fact, if anything, the fact the Net was free did more to boost surveillance capitalism than anything else.
If companies actually had to pay to collect, hold, operate on, and be privy to information about people; In Short, if there were acknowledged data privacy rights in play with regard to people's meta-information, and it was not just handed to corporations as a blank check money making asset, surveillance capitalism couldn't have gotten off the ground.