There is no easy answer to that question to my knowledge. All of what hospitals do is translated into the Dutch equivalent of diagnosis-related groups. Those DRGs are standardized across the hospitals doing procedures. Insurers bargain with hospitals (usually on a higher level) for price-setting. So while there are DRGs that probably have a large IC-component, most have only a little. So the costs of IC are reimbursed via all treatments that have an average IC-component.

A hospital with a good cost based activity system could probably tell you more, although that would require a very high measure of control.

Dutch press just reports the general direction of (internal) prices for IC-days (about € 3k / night). That really is nowhere close to the proper answer to the question "How much would expansion cost?" The sum based on that € 3k would be: €3k * 365 * 65% * 1200 = about € 850 million for the whole of IC-care. That is a low figure for the Netherlands (€ 25 billion total medical specialist care), so I expect a lot of the IC-costs are absorbed by other DRGs or the other way around: that price doesn't include all of the fixed costs and is a marginal price.