Mick - I would say that the 3 drilled wells enabled the buyer to offer you a more aggressive bid than what you previously received. One of the largest challenges a buyer of mineral interests face is the uncertainty of timing (assuming they can analyze the geology, etc).
As it relates to Bruce's original question, Bruce
There is a good deal of activity in your area. You lie slightly north west of the historic focus in the Arkoma Basin, However, several companies are looking at applying more modern/advanced completion designs in the overall Arkoma basin. While you are outside of the historic play, and therefore more 'exploratory' you have a number of items in your favor that should help support values for your acreage. In 2015 and again 2016, Bravo Arkoma drilled nice wells in section 14 (about 2 miles to your south west). And Bravo drilled another nice well in section 15 2016.
Calyx has two wells permitted due north of you - top holes in 9N11E S36 with bottom holes in S25 & S26. The results from those wells will have an impact on your acreage value (either positive or negative). I think the biggest challenge you will face as far as downward pressure on acreage value is the uncertainty of timing to development.
All in with nearby successful wells, and the overall land rush, your acreage should see an uptick in interest and value.
If you want to dig deeper - please give me a shout, always happy to help.