Bette,
Unsolicited offers from non-producers are often an attempt to tie up your property for a long period of time while the “buyer” finds a way to make a profit by selling at a better price or discounting the purchase and sale agreement with you or both. Remember that buyers are in the business of buying low and selling high at the lowest risk possible. NO BUYER WILL OVERPAY!!.
The Bakken Geologic System is a very dynamic oil province that will be continually changing as exploration and development continue. If you are in Williams, McKenzie, or Mountrail Counties (I could not find McKinley County) and indifferent as to ownership of minerals, I believe you will enjoy a long term economic advantage of holding and conservatively investing the royalties from your existing wells and the multiple of wells yet to be drilled. However, if your lifestyle would be enhanced through the sale of an asset, after taxes of course, you may consider what that net after tax amount would be, then get some professional advice as to the true value of your minerals to a legitimate buyer and set a sale price. You then can solicit buyers that may be interested in your minerals with a lump sum offer to sell. If you close a deal under that concept, everybody will be happy.
Location and control of oil resources is key to value for the foreseeable future. Last year, I valued family owned Williams acreage at $10,000-$60,000/acre based on current technology. If anticipated research and development prove to be sound, those rates could double. A buyer’s needs for Return on Investment will be the determining factor in what it will pay when factored by ownership determination, risk aversion, cash availability, opportunity cost, asset control, name a few. Buying and selling minerals, like single family homes, is not a retail business.