What is the value of Mark Twain's Tom Sawyer published by Goldsmith publishing in Chicago in 1876?

I don't believe the Saalfield company was started until 1900, and I believe the original publisher was American Publishing Company. Although, I believe it was published first in Brittan by Chatto and Windus due to due to copyright difficulties. However, it is possible my research is wrong, so verify for yourself as well.