The three grammes of copper in the 1 rupee coin (we are talking about the older style, the Jinnah on one side, Badshahi Masjid on the other, a brown colour, not the newer silvery looking coin) therefore has a refined value of 2.64 US cents.

FORBES: The Pakistani 1 Rupee Coin Is Worth More Than 1 Rs

The flaw probably happened because of Mr. Brown's imprecise work casting the planchet the copper and nickel blank disc used to create the coin.

WSJ: Rare 1913 Nickel Auctioned for $3.1 Million

But a 20-30% discount on the copper value is reasonable enough thus making, at the refinery gate, a 1 rupee coin worth perhaps 2 cents or two rupees.

FORBES: The Pakistani 1 Rupee Coin Is Worth More Than 1 Rs

Up to 2500 rupees if you believe the rumours sweeping Pakistan that the humble coin had inadvertently been made with gold instead of the usual tiny percentage of copper.

FORBES: The Pakistani 1 Rupee Coin Is Worth More Than 1 Rs