photo credit: KittyCanuck
From first-hand experience, when you’re selling something on Craigslist set the price for some multiple of 20—this way you don’t have to make change as your buyer will have likely just gone to the bank machine and have twenties in their pocket.
I took a photo and released it under CC because I figured some1 might need it like I did, and some1 used it! :D http://tinyurl.com/y9o9yld