There have been a lot of discussions recently about bringing back engines like the UP big boy to operating shape, and obviously the significant expense to do so. It led me to thinking about a more extreme case, that with engines that did not survive as a class at all (i.e NYC Hudsons), let's say someone really had money to burn and was enough of a railfan to want to bring something like that back to life, had a set of original builder plans, etc......the Fermimath question of the day is, how much would something like that actually cost? Obviously it is going to be extremely expensive, I am talking someone with Warren buffet like resources here....... It would have to be in the 10's of millions, for sure, given that most of the parts and such would need to be custom fabricated, and foundries and such to do that kind of work are not easy to find....
Your guess, and why you came up with that figure?
(BTW, the reference to Fermi math is a reference to a really fascinating program for kids. Schools put together teams, and they are given problems that don't have clear and concise answers (in other words, not for training future accountants and finance types)....so for example, they are given a problem, to estimate how far the world's oceans would fall if all the ships and boats in the world were removed suddenly, which requires estimating and working with something where there is no clear cut 'right' answer..and they have to show how they came to their answer, it is part of the competition).