I cannot comment on “fair”, but I always ask myself, “what do they know that I do not know” and I am pretty sure they intend to make a profit off of me, so would attempt to find out if the offer is more than the value of the current well and if there are more wells planned. Most of the offers I have received have been less than the value of the current well (taking into account oil and gas prices and the time value of money over the production life of the well).