A few weeks ago I found a bottle of cutting board oil at the Home Depot and was almost tempted to buy it, but didn't want to spend the money that night. It was $8.98 for a 12 oz. bottle. I needed some for my wooden spoons, cutting board, and a new pastry board that I had purchased awhile ago from IKEA.
But now I am glad I didn't. After researching cutting board oil on the Internet, I learned that it's basically mineral oil, which can also be purchased in the laxative section of most pharmacies. And sure enough, mineral oil (enriched with a little Vitamin E) is the main ingredient of the Home Depot version.
I found a 16-oz bottle of mineral oil today at Walmart for $1.99, which was not only 1/4 the cost of the other bottle, but had more oil!