From reading the 10A/Q filings, I understood that the Cognate agreement is basically a production cost plus pricing model with minimum guaranteed payment amount. If this is the case and the cost plus pricing is guaranteed and contracted with Cognate and then it is reasonable for NWBO to pay for all the fixed costs of manufacturing infrastructure build as far as it is dedicated to them when they need it.
It would have cost NWBO more to build and own the manufacturing infrastructure themselves and keep idle capacity until commercialization. Any other non-related contract manufacturing partner will likely not be willing to take the risk and incur the fixed costs themselves upfront.