Good Luck with That
I can't think of anything that costs a single penny and only a single penny. Can you?
That seems to make Buy Something That Costs $.01 Day kinda worthless, doesn't it?
Pun intended.
If you know of anything for which you can spend the grand total of $.01, let me know. This does not mean $.01 plus shipping and/or handling. It means $.01 grand total.
In the absence of getting anything that cheap, you can perhaps substitute getting something worthless instead.
Go to just about any garage/yard/rummage sale in your neighborhood and look for the "Free Box".
Speaking of rummage sales, there's an outside chance that you could find something there for just a penny. Even most rummage sales though charge at least a nickel for anything outside the Free Box.
If you like to barter, maybe you can whittle them down to the area of $.01 per item.