Artist's proof - original signatures and numbered

I acquired this print from someone I knew that worked at The Greenwich Workshop. It is an original numbered artist's proof entitled "Lake of the Shining Rocks." It is my understanding that Stephen Lyman passed away unexpectedly quite a few years ago. It is also my understanding that his wife is signing his prints now. This is an original Artist's Proof that has his original signature from before he passed away. It is #27 of 50. That is all I know. Any other information would be greatly appreciated. The proof itself is still in the original packaging and stored in a safe dry place. I am debating on whether to have it framed. Does anyone know if original signed Artist Proofs are worth more than prints?