Lease - Is Diamond Resources the only option, and what is a fair rate?

My 90 year old grandmother received an offer from Diamond Resources about a year and a half ago. I suggested she wait and see if she got a better offer or if the play heated up, but it doesn't look like either is going to happen quickly.

We would like to find out who all is buying leases in the area and what a fair price and terms would be.

The description of the land is as follows:

Mineral Deed covering lands in Weld County, Colorado

Township 2 North, Range 63 West of the 6th PM

Section 19: SW1/4, except a parcel conveyed to The Burlington and Colorado Railroad Company by Warranty Deed recorded November 1, 1890 in Book 97 at Page 235, also except a parcel conveyed by Leah C. Walter to Jack D. Helermann, Jr. by Warranty Deed recorded July 22, 1992 in Book 1344 at Reception Number 02296642