Mineral rights help leasing in Burke County, ND

I received a letter from Open Range, Inc. They currently hold an Oil and Gas lease on my property in Burke Co(Twnship 163, Range 92, Sections 6,7 and Twnship 164, Range 92, Sections 31,32) until May 2013. In the letter they state they have obtained well licenses for 2 spacing units at Twnship 163, Range 92, Sections 5 and 8 and go on to site several difficulties in establishing a spacing unit for drilling of my property so they want to extend my lease, which is set to expire on 5/13/2013, for 3 more years and are offering $150/acre for 37.57 net acres at 1/6 royalty-signing date of 12/21/2011. My question is why do they need to release now when the lease is not up until 2013 and is 150/acre with 1/6 royalty a lowball offer and do they hope we will release before any production in this area so they can pay less for lease.