With stock and price varying by ZIP code, Home Depot offers the Irwin Strait-Line Marking Crayon 2-Pack in Red, Black, or Yellow for 78 cents. Opt for in-store pickup to dodge the $5.99 shipping charge. That's $0.39/crayon, tied with our mention from two weeks ago, and the lowest price we could find by $3. These waterproof crayons are for use on lumber, concrete, ceramics, and metal.