The Transport costs etc are in the DFS, makes no difference...

The Transport costs etc are in the DFS, makes no difference transporting DSO or SP6 - all the same cost to transport.
Costs will have gone up since the DFS, but even with a 50% increase, it should still be profitable

From the DFS
Transport cost A$69/t
Open Pit mining cost A$28/t
Processing cost A$22/t (would only need crushing, not grinding + flotation so would be cheaper)

As I said above those costs will have increased, there is still Royalty to add, the State royalty is higher for unprocessed 7.5% vs 5% plus the private royalties and the undisclosed native land owner royalty.

Those costs could also go up because of the loss of economies of scale doing spot DSO vs the 20 year LOM average costs

Remember too, the above are in AUD whereas sales are in USD
And I believe (??) that ore had to be moved (mined) anyway to access the better grades below it?

Yes Leo (which I also own) are saying $300/t, however I think they are being ultra conservative.