Mine/al Sale : Negotiate % of royalty

Can’ I negotiate a royalty in a mineral sale and if so what mught be a fair percentage to ask?
Anybody hear anything about SEC 20? I know in the early 80’s There was a lot of hot interest. But since the oil bust of 1984, its like it fell off the ends of the earth.Any info would be greatly appreciated.

         Thanks,  Wes Tucker