Does anyone here know the value of my 1931 first edition "Essays in Persuasion" by JM Keynes?

Fair condition. Missing jacket.

So I found this book today at a garage sale. I had no idea how much it was worth, but apparently it is a pretty valuable piece. I googled it and found a few different prices for it (300-1100 USD) but I would like a more definitive answer. Thank you.