I buy a lot of chemicals in my business. The prices are double what they were 4 years ago because they are petroleum based. We've turned to alternative enzymes because they are now cheaper than conventional chemicals for the first time in history.
We were looking into getting exterior foam insulation for our flat-roofed home a few years ago (2004 maybe?!?!?). The cost was massively dependent on the price of petroleum. It was $5K to $10K a few years ago. I shudder to think what the cost would be today.