It is supposedly $750k for the Canepa "restoration". But that is for a car that is in fine shape I'm sure.
So I'm not sure how much extra it would cost to get it fixed first, but that is something they could provide.
Even if the car goes for $500K in its current condition (we're talking all USD here) and then you add the $750k (let's call it $1m in case you need to pay extra to have it fixed) you'd be at maybe no more than $1.5m for a basically brand new and upgraded 959.
Considering good examples at auction are going for $1m, and will probably be going higher in the near future, then maybe it would;t be a bad investment.
However the Porsche that bring in the most money are typically the most original...
I'm not convinced that a Canepa car would necessarily bring any more value to the car...
But if that is something you don't care about then buying this wrecked one and paying for the fix and restoration would probably end up being a "good deal"/