You can look up the Wikipedia article on almost any comparable ship and see how much it cost to build. I have done that for several examples, and I would guess

You can look up the Wikipedia article on almost any comparable ship and see how much it cost to build. I have done that for several examples, and I would guess that a passenger ship compliant with all current regs and standards and carrying ca. 3500 guests would cost ca. USD$1 billion. So that’s roughly the adjustment for inflation. Also adjustment for the new regs and updated regs since Titanic.