coking coal premium?

Hello,

Could you explain how a company Bathhurst (BTU) have a market cap on their coking coal of 360 million with coking coal reservs of 42 million tonnes (production late next year)

Coalspur have 1.37 billion tonnes (thermal) and market cap of $760 million (production years away)

Looking at a per resource tonne value cpl: 55 cents per tonne and btu: $8.50 per tonne

Why does coking coal have such a premium, when it is only double in price?

Thank you for any help

Nick