While these buildings should not have been levelled in the first place it seems foolish to build them now. They will be levelled when Ukraine reclaims the city and Russia will have to pay to build them again. I would prioritise rebuilding the hospitals / medical facilities that were destroyed to treat the sick and provision of food, water, clothing, essential services and then residential / schools.
It also seems more a modest venture or a vanity project than full swing. I'm guessing size and method of construction would put it in the £20,000,000 bracket. This is not a lot considering the £billions required.
I'm also guessing the foundations will be subject to ground penetrating radar to ascertain what lies below.