Batelle District mineral rights valuation and lease vs sale

We are heirs to mineral rights to all gas, oil, and coal on a small parcel in the Batelle District of Monogalia County West Virginia. Three siblings share mineral rights to 1.99 acres. We do not own the property. Target likely is Marcellus Shale gas.

We each were offered $8,000 for our mineral rights on our small parcel. We generally feel we might do better if we hold on to our rights and wait for a future leasing opportunity. But, we have been advised by an attorney (pro bono) that there is a law in WV that allows hydrocarbon producers that are unable to gain control of all mineral rights in tracts where they will frac to proceed anyway. To do this the producers need only to obtain mineral rights on a specified percentage of the tracts in order to extract from the full acreage. In this event a producer must pay the owners who did not sell their mineral rights the average per acre price paid to owners who agreed to sell their rights.

We are asking here, from persons knowledgeable, if the $24,000 we three siblings would collect from selling our mineral rights is a reasonable purchase price or at what valuation a counter offer would be appropriate.

Thank you for your consideration,

Jim B

Correction: each of the three siblings has rights to 1.99 acres and each was offered $8000 for their rights, so the valuation is about $4000/acre. Is that a fair valuation?