I do not know specifics about the size of the Chromite resource that Freewest has because I never owned that stock thus take only cursory interest but it seems high when I have seen mentioned as little as 50 million tons.
Next is that usual percentage for an in ground resource is 1 to 5 percent and not ten.
Ten only when you are about to build a mine. That means 43-101, feasability study, some assurance of financing some permits. I do not think 10 percent applies to Freewest. I would guess 2 percent.
Similar with chromite price. I have seen prices mentioned as low as $75 ( try a bit dated and one third down: http://mysite.du.edu/~jcalvert/phys/chromang.htm ).
If one starts with the worst case scenarios of the above you have a third of the recource mentioned, one quarter of the price per metric ton that already means a drop by 1/12 and if one uses my 2% that means a further decrease by 5, results in total decrese by 60.
Take that $20 divide by 60 and what do you get?
Price valuation is a bit of an art form and it is mostly in what assumptions or guesstimates one uses.
One's pump is another's bash.