CLA chart, page-1531

It's more than a $6mil question, but fairly simple.
5,000t of Co would be a ~5mt plant at the recovery rates we have been given so far.
The size of the plant actually selected will be dictated by all the factors surrounding, well, everything.
That's what the Scoping Study will give our first 'rough guess' at. If it all looks profitable, it will go on to more accurate Feasibility Studies (Definitive FS - Bankable FS etc).
Considerations would be Capex to establish the plant and infrastructure, Mining methods and costs, Opex costs, estimated Cobalt prices for the future, Transport logistics, plant at Walvis Bay to refine into Cobalt Heptahydrate.

(And everything else that a paid professional company would need to consider, quantify and justify rather than a guy at a keyboard typing a 2min response).