That's a lot of stuff, but as you indicated, you are going to be interested in just a portion of that "stuff", right? What are you going to do with the rest of the stuff?? If you are going to sell them off, then there will be some effort and expense on your part. If you aren't going to sell them, they will hold no value to you. Do you really know if chemicals and papers are good? If you are going to sell them, would buyers be able to trust the product?
Sounds like to me... the decision to make is not only what's it worth as a whole, but what you intend to do with rest of the stuff, and that will determine what the fair value TO YOU would be.