How to find chemical market value
Until 2005 or 2006 the best source was Chemical Market Reporter.
It had the form of a newspaper and was edited once a week. 
The last pages listed market prices for commodities, some speciality chemicals and also agricultural products. 



Hundreds of products were listed and you had some idea of what were the options you had for designing an industrial process. 
You could easily decide which solvent to use for an extraction, which metal for a reduction or which raw material for a synthesis. 

The publication was on subscription base but it was available in some University libraries or you could get an older copy from a contact in the big chemical industry. 

Now this has been converted on a pay per product information scheme. 
You can enter in www.icis.com and ask a report for one product. 
If you want to compare prices you have to buy the information for every product. 
It is almost impossible to have a complete picture of the economic trend in the Chemical Industry.