I would think an estimate from the artist (i.e. Larry in this case) to re-create the painting would be what you want. I'm guessing the $5 range, give or take.

Please email me a photo of the art so I can remember which one it was and I will write you a letter giving you the market value. Email me at larryelmore@gmail.com
Thanks...oh yeah, no charge for the esitmate.