At the start of the sale.

We survived the yard sale, despite great heat and vast inexperience. In the end we sold almost everything, barring old computer books and random ugly pieces of glassware. Although you'd never know it to look at me, I come from a long line of the merchant class and there's a certain amount of merchandiser in me, so I amused myself by writing witty things on the price tags and wheeling and dealing a little with the crowds.

Final scorecard:
Amount of money I procured in small bills (to make change) on Friday afternoon: $100
Amount of that change I needed on Saturday and Sunday: $0 (most people paid in small bills, oddly enough)
Number of people who wanted to buy the not-for-sale radio: 4
Number of people who wanted to buy my merchandise tables: 2
Number of people who wanted to buy the chair I was sitting in: 1
Number of people who wanted to buy the plastic tablecloth I was displaying merchandise on: 1
Number of people who tried to pay me in Tootsie rolls: 1 (did not succeed)
Number of friendly bookworms who bought lots of books: 3
Number of CD browsers who knew who Momus is: 1 (yes, I sold The Little Red Songbook! I confess!)
Number of people who wanted to buy my old microwave: 2
Number of people who wheeled it away on their bicycle handles: 1
Bottles of water consumed by me: 3
Times I worried about rain: 4
Times I worried about being undersold: 1 ("what do you mean, books for a quarter?")
Number of Anais Nin books for sale: 3
Number of Anais Nin books sold: 0
Times I was asked if I was an English major: 3
Number of old ladies who wanted to buy my table and then shouted "BUMMER!" when I said it wasn't for sale: 1
Number of people who bought old computer books: 0
Total expenses: $10 (community sales fee, plastic tablecloths, masking tape)
Gross profit: $75.32
Net: $65.32

You get the idea. See you on the sidewalks next year!