Putting a value on unique park memorabilia

Hi everyone! I used to be involved in the enthusiast community, and am also a former Cedar Point employee (talking 10 years ago, yikes I'm old!).

To be succinct, I have a lot going on in my life now, and am trying to minimize my possessions because it's quite frankly a pain to have to move them around constantly. Most things I can sell or donate locally, or throw out, but there are some things that I acquired as an employee of CP that I feel like would be better offered to the enthusiast community, because you all would appreciate them more.

Specifically, the items I'm not sure about putting a price on, as I haven't seen them being sold anywhere else around, are my two SOP manuals for Magnum XL-200 (2001) and Millennium Force (2002). I do feel like somebody might appreciate these enough to pay for them, but I don't really know what kind of price to put on them. So has anyone bought these kinds of things in the past? What should I be looking for, if anything? Condition of the covers of both of them is fair to poor, to be honest, but the pages of both are completely intact and perfectly readable.

If this is an unacceptable topic for here, I apologize. I am not trying to sell them here, I planned on listing them.