Seeking advice

I published my first poetry book around 2005. The book is called THE SCIENCE OF CHOCOLATE MILK MAKING. Unfortunately the publisher passed away shortly after the book was released. It was a new and very small press. The book has been selling for years and I have never seen a dime from those sales. For some reason the book is selling now for over $150. I don't understand why. But it is. I know for a fact it's selling because I have signed copies for folks who paid that much for it. In the beginning I was on a quest to get that straight but got nowhere and then gave up. My thought back then was hey, it's my first book I'll write another book. But now I would like to revisit that and don't know where to turn. If you have suggestions I would appreciate that. Please please please don't add comments will not forward this. If you can help that would be great. If not your thoughts and prayers are appreciated. I don't know why I am nervous about posting this but I am. I share a lot with you but for some reason I'm sensitive about this.