Need help pricing Keane Big Eyes

I've always felt this was valuable long before the movie, even when it was creeping me out as I caught glimpses of it in the middle of the night lol. It was always hanging in my great grandfather's house much longer than I've been alive and he didnt have much that was cheap or poor quality and I instinctually wrapped the hell out of it when packing the house. I've seen many items selling well due to the Illinois moulding co. name and obviously anything Big Eyes these days but what exactly determines the value? Plaque at bottom reads " no dogs allowed Walter Keane" , back stamped with some type of serial no. "V1108-496 NO DOGS ALLOWED" and "ILLINOIS MOULDING CO. CHICAGO 8, ILLINOIS" in red ink.
No way it's an original huh? Helppp!

 

It looks to me like a print, but I can't tell for sure. I found one online for $1200, another for $600, and a third for $60.

According to online, original paintings can sell as low as $1000, or as high as $45000. I can only imagine this is their value as iconic pop culture.

I'm not a fan of these pictures, but they were enormously poplar and I'm sure that says something about people's state of mind. Sentimentality is a cornerstone of Kitsch. I just looked up the grand masterpiece "Tomorrow Forever" and it made me shudder.

Here are excerpts from the John Canaday review that apparently gets covered in the movie (which I have not seen):

https://www.vanityfair.com/hollywood/2014/12/big-eyes-tim-burton-walter-keane-new-york-times

 

I agree, looks like a print. That type of tag is typical on mass produced items. I see these in shops quite a bit, never with the Walter tag though. The movie is worth seeing, it is well done.