Selling the Book of Mormon Copyright

In 1829 Joseph Smith claimed God had told him to send Hiram Page and Oliver Cowdery to Toronto, Canada to sell the copyright of the Book of Mormon. Interestingly enough, their mission didn’t go the way Smith’s revelation said it would. Smith’s response to their ventures is found in the David Whitmer’s “An Address to All Believers in Christ”, pg. 31, “…some revelations are of man: and some revelations are of the devil.”

Wouldn’t God have known they wouldn’t sell the copyright?

Why would you trust someone who sends people out on a mission to do something with results like this?

Why would you trust someone who doesn’t know if a revelation is from the devil?

Would you trust this today?

What about Deut. 18:20-22 which tells us that if even one thing isn’t true from a prophet then we’re to disregard what he says?