Rusoro's offer doesn't even cover GRZ's cash and equipment. They aren't offering $4 a reserve ounce of gold at all. They are offering less than zero for all of Brisas' 10.4 million ounces of P&P gold, a few billion pounds of copper and the very prospective Choco 5 (which they have already sneaked onto and drilled without GRZ's permission).
GRZ's cash and equipment is worth around $120 million or over $2 a share without any property or reserves. Rusoro can state the opinion that Brisas' gold is not worth anything without a permit, but he isn't offering anything for it either.
It is worth at a minimum, the cost of drilling, assaying, engineering and the permits already written and approved, a total of $300 million or so. Anyone starting from scratch would have to pay that sort of money or more and take years to be able to advance the property any further without duplicating that work. It costs a minimum of $30 an ounce to find gold and prove it up to P&P status in areas of known ore deposits and lots of exploration efforts spend millions and get nothing commercial at all.
One question that Rusoro hasn't touched on though... Will their self professed "preferred status" last and how many skeletons will be found in their Venezuelan closets if Hugo loses an election and the government changes?