There is no one, credible source for current & historical prices of bulk chemicals available for educational purposes.
Two publications with a focus on chemical prices:
ICIS Chemical Business - Available electronically (2007-present) through the database ABI/Inform. 2006 issues available electronically from the database General OneFile. Recent print issues available in Current Journals area (1st floor) TP1.O3.
In current electronic issues, search for "chemical prices" to locate a table that contains spot and contract bulk prices for a few industrial chemicals and petrochemicals.
In older issues the chemical prices table was called "key indicators" and found in the Market Trends & Data section.
Chemical Week - Most issues (1987-present) available electronically through the database ABI/Inform. Recent print issues available in Current Journals area (1st floor) TP 1 .C512. Search for the CW "Price Report" section or the "Product Focus" section for specific chemicals in older issues. The price report contains mainly spot and contract prices for a few select bulk industrial chemicals and petrochemicals. Note: It appears the CW Price Report section was discontinued in 2012.
Chemical supplier websites may include prices. Please note that small scale, laboratory prices may not be appropriate for bulk quantity pricing.
Print Resources at the library
Aldrich Catalog -- TP202.A54 REF
OPD Chemical Buyers Directory -- TP12.O3 REF - Also online at www.OPDsearch.com
Chemical Week Buyers Guide -- TP12.C713 REF
Handbook of Industrial Chemical Additives / Michael & Irene Ash -- TP201.A84 REF
Lab, research, specialty
Sigma-Aldrich - http://www.sigmaaldrich.com/
Chemical.net - http://www.chemical.net/
Chempoint - http://www.chempoint.com/
Plastics Today - https://www.plasticstoday.com/