How do I find the value of a misprinted Harry Potter book?

First/first UK edition? Inscribed by Tolkien? With the original dust jacket? I’ve seen one listed for over $100k.

Bingo!

Would a First/first of the the first Harry Potter book (Harry Potter and the Philosopher’s Stone) be worth something?

The UK first certainly is, yes - tens of thousands of dollars in good condition. There were only a few hundred printed, and many of those went to libraries so they’re not pretty.