Older issues of journals that include chemical pricing information are available in print.
Try these prececessors to ICIS Chemical Business:
Or access older print issues of Chemical Week:
Encyclopedia articles can provide economic indicators and prices (here’s an example). These encyclopedias have entries published over a range of years, so note the publication date when you get to an article.
Search for your chemical in:
Covers all aspects of chemistry and chemical engineering. Many of the articles on chemical covers uses, manufacturing and processing, and economic aspects.
Articles on all topics in chemistry and chemical engineering, including production, uses and economic aspects for many important chemicals. Good complement to Kirk-Othmer.