The cost of building the Obama memorial will be very big, I'm sure.
But the budget for 24 hour guard perimeter is going to be enormous. Maybe a special tax on spray paint can help cover the cost.
I can't imagine any reason why the Jefferson Memorial shouldn't be taken down, if that is the will of the people. No doubt there were costs paid to erect it and continuing costs to maintain it. The poor man is long ago gone to this world but his spirit lives on in vastly more important ways than this memorial.
I think we get too upset by a bunch of this crap. Tear the dang thing down. It will probably cost multiple millions to do so. But it's ok, we have money to burn. As Americans, that's just what we do. The politicians have all the money. We have a self reporting, voluntary tax system. We support these guys with real money.