I'm fond of beam antler, I drill it off center and I like the look of marrow showing up on one part of the blank only. I find that pens that show some marrow, or better yet showing some bark, sell better than perfect surface tine antler pens. Deer hunters seem to prefer some character in the antler.
Recently I traded some pens for a large pile of corn fed, farm raised whitetale antlers. The grain fed whitetale have almost no marrow in the antlers. If these antlers had been perfect with buttons they would have been very valuable in the taxidermy trade, but they were mostly broken, mis-shaped, or otherwise not good enough; they make great pens, but they do tend to be grey, not white like a elk antler.