My understanding is that there will be $50k plus 1M options...

My understanding is that there will be $50k plus 1M options (returning $250k to HVY if converted) paid to fosters to find investors willing to invest $2M cash for a royalty.
There is dilution if the options are converted. around 2.2% dilution on current soi.
That royalty would likely be in the form of a percentage of sales. The terms are not provided yet but let's assume the $2M attracts 1% royalty for PG's life of mine and sales are $40M p/a for 16 years.
0.01 x $40M = $400k p/a. I have no doubt Fosters have investors lining up for this deal.
Again, the terms are not visible yet so I am speculating the figures.