In all my long years working and living around pine trees, I've seen only a hand full of Pine Burls that can be called such but, yours will top all the ones I've seen so far.
That piece you've got there, is a very, very rare find, I doubt you will ever find another like that, in your life time (I will be glad if you do...!:wink
I don't think, you could have turned it or made a display/decorative piece, using any other shape, the whole surface (in and out) of the burl is to precious to waste into savings/sawdust, and while I can understand why some exclusively pen turners, see it as a shame not to have been cut up as pen blanks,:frown: I can also understand why sometimes ,that decision is not taken that likely as nothing will compare to the burl sliced where all surfaces are expose, particularly the "full" inside area on the burl.
Another fact is that, if I was the one to find it and had decided to cut it into pen blanks for sale, as soon as you advertise anything with the word PINE in it, you are pushing a wheel-barrow full of lead, up a steep hill...!

.
Most wouldn't even look and others would buy it if the price was very cheap and sell it as Burl from something else but never pine, that I can guarantee to you...!
Even with all its "rarity" tag, asking for more than a couple of dollars per blank, you would be called a full. On the other hand, any pen blank cut from those areas with all those pretty eyes, and in the hands of these same people, would be put in a high-end kit and would have a price tag of between $200 and $400 (at least) and marked as some rare exotic burl material from Mars, (possibly)...!

How do I know...??? I've seen it done, at regular basis with other woods...!:wink::biggrin:
Nevertheless, I'm glad you kept it in one piece (I mean 2 pieces) but now that you've got half done like that, you can use the other half to do smaller stuff, including some pens, if that pleases you...!
Good luck...!
Cheers
George