5 & 1/2 months, page-3

That 1.5 tonne is a test batch.
Seems that the Japanese have raised the bar on PLV and have possibly requested a specification greater than that achieved via any CSIRO testing to date.

Could also be, that to achieve the spec PLV will need to enhance their expected benification process.

Might add to the cost of production, but even so, seems that the trading house is willing to pay a premium.

So, PLV's job COULD be to produce a higher spec material at a cost the trading house will still consider reasonable.
Note the comment on PLV's last release:
"Key to any financial transaction is Pluton's ability to show that it will be able to meet the required technical specification and cost requirement..."

Sure, there is some speculation here but PLV's release leaves little choice but to speculate.