The calculation between the sale of Li2O and the sale of Li2CO3...

The calculation between the sale of Li2O and the sale of Li2CO3 is not easy. It is comparing apples and oranges.
Let's have a quick go though. One tonne of Li2O makes about 2.47t of Li2CO3. The spodumene we will be selling as a concentrate has about 5.5% Li2O, so we need about 18t of our spodumene concentrate to make 1 tonne of Li2O. Using PAST prices first, we would be receiving about $450/t for our concentrate, so 18t of it would produce income of 18 X $450 = $A8100.

However this turned into 2.47t of Li2CO3 by the chemical makers, when the price was $6000/t of Li2CO3, so our $A8100 was turned into $US14,820. So Dicondra's original numbers are not bad, but there is an operating cost as well as the capital cost to do it.

Now though, the price of the lithium carbonate is getting up to $US20,000 on the spot market and up to $US12,000 in new contracts, so at least double the past!! As just a spodumene concentrate, we should now be able to get up to $A900-1000/t with the new pricing, or $18,000 for the one tonne of Li2O!!
But as a finished product get $US30,000 from the same product with a supply contract, or up to $50,000/t (of original Li2O) from turning it into lithium carbonate on the spot market!!!

My own opinion is lets walk before we run. Let's start getting income from selling concentrate first, before we look to expand to a carbonate (or hydroxide) plant.