Going current price per acre for mineral leases north of Carlsbad, New Mexico

I just got offered the same money $150 per acre for 5 years that I got for a 2 year lease on the same land in 2014. In this particular area, does anyone know what the fair "going" rate per acre is right now? They also offered $750 per acre to buy the mineral rights...which I'm not selling. Is all this VERY lowball or average considering that the big oil "boom" in the Carlsbad area is basically over?