Except steam generators are pretty cheap - they're off the shelf, and will be a drop in the ocean compared to the total costs of the first fusion plants.
Well, that depends. ITER is tens of billions. The most expensive part of this reactor would probably be the petawatt laser, which is tens of millions for one-off experimental devices. A turbine and generator is about a million dollars per megawatt, so it could be a significant percentage of total reactor cost, especially in mass production.