What is the value of a first edition of Alice in Wonderland?

In 1998 a rare first edition of Alice's Adventures in Wonderland was sold at auction. It went for $1.5 million US. That particular edition was Lewis Carroll's own copy, and contained annotations by Carroll and ten original illustrations by John Tenniel.

Only twenty-two copies of the original 1865 edition are known to still exist - seventeen are in libraries, and five belong to private owners.

It is impossible to attach a value to them, as their worth is unknown until somebody actually sells one. They are, literally priceless.