According to this article, the CRV total development costs are supposed to be under $500 million. When you consider that at least one flight on the Shuttle will be required to validate the system, well, that's very cheap by manned spacecraft standards. By way of comparison, the projected costs in 1959 for the Mercury program were $22.8 million for Atlas boosters, $16 million for Redstone boosters, and $49.4 million for the capsules. That's a total of $88.2 million. The actual costs were much higher. Factor in inflation and the Mercury program cost about the same as the CRV. The inflation multiplier (use the Inflation Calculator on the CPI home page) from 1959 is 6.11, so those projected Mercury costs come out to $538.9 million.

As another cost comparison, the original projected costs for the Gemini program were $250 million in 1960. Those costs tripled to $744 million by 1962. The inflation multiplier for 1962 is 5.88, so the Gemini program cost $4.37 billion in today's dollars.

The plan is to build a few of the vehicles so they can be rotated in service. I don't know if that development costs cover just the first vehicle or all of them. Furthermore, Europe has expressed interest in building the vehicle. Just because something needs to be done, it doesn't necessarily mean that it has to be done (and paid for) by Americans.