@jstill,
People who deal in art guard their knowledge jealously. There are certain websites that list prices that paintings and prints have sold for at auction, but they tend to be for members only and the price of membership is very expensive, usually thousands, not hundreds, of dollars.
Having said that, prints don't tend to go for that much. You could search for similar items on ebay to see if they've sold recently but don't hold your breath.
I have an original piece of artwork by an artist who has been exhibited in major galleries. I found another piece by her on ebay, the seller wanted £500 for it. I followed that item for two years and it was never sold.
Still, it's a nice painting and it looks good on my wall.