The price of coal was lowered from $1.00 to $0.40 recently. I asked and was told this was because wood can be converted to coal in a cooking pot. My suggestion is two-fold: 1. Make cooking pots convert wood into charcoal instead of coal. 2. Change the price of coal back to $1.00. Mining received a collateral damage nerf from this price change, and this is a way to avoid that.
it will take them time or they will have to wait for a pluging update to change it, they will most probaly be changed back once its fixed