'79,
O&G attorneys like queso are invaluable in supplying, for lack of a better term, a source of 'comps' for bonuses and royalty percentages in a particular area. Oftentimes, they know the players in an area and what the current bonuses and royalties are, simply because they've been negotiating leases with the same players.
You may wish to make a call or two in that regard.
Also, I would recommend you visit the Midland County Group on the Mineral Rights Forum.
Midland County O&G ForumWhile I've always been very guarded discussing numbers in a public forum, you'd be surprised at what you can learn about current conditions and operators just by reading the posts.
You'll have to join the forum, but that's no big deal. I see there was activity as recently as this past Friday.
Good luck. Smaller tracts don't have much leverage in negotiations, but at least you'll know enough to make a fair deal.