It is common for commercial aircraft prototypes to cost from 10- to 20-times as much as the production units. Proper financing and scheduling of production runs means that companies often break even after 40-60 aircraft come off the production lines.

If this new space plane were intended for mass production, say an order of 80 units, then the costs could break down as follows:

Total revenue from sales = $ 9,600 million (80 units @ $120 million each)
Development cost = $ 2,400 million
Production costs = $ ???? (3 years to fill order)
5% incidental costs = 1.05 x Production costs
--------------------------------------------
Profit = $ ????

I doubt the company that produces the vehicle cares what happens after delivery. Operating costs are sometimes, but not necessarily part of their business. It would be up to whoever purchased them to turn a profit from flights. After all, they had to justify ordering them in the first place!

No doubt you're thinking "But! But! This is a spacecraft, not an aircraft!" LOL. It's a fair bet that whoever builds it will cover their bottom line adequately. The fact that they are paid by tax dollars is irrelevant after the contract is signed.