How much is my Grandma Moses print worth? I've tried to look online, but I suppose I don't know where exactly. Google is no help.

It’s about fifty years old, it’s the “Country Fair” painting, but a print. I got it from an old friend, it belonged to his grandmother. It’s in excellent condition, in the same frame she put it in, and not stuck to the glass or the backing. I took it out and put it in plastic. Can anybody help?