Some books shouldn't be read.
A deal (contract) is made when terms have been agreed on. This for that. In writing or oral. Both parties in agreement.
Not choosing sides just pointing out what is considered a 'contact'.
Now if you've agreed an a price, and set a time limit for payment or pick up, and it wasn't. Then you had the right to offer the items again at any price- combo you want.
Hope it was just miscommunication and it works out for both parties.
This. In my state, an oral agreement is a binding contract and enforceable in court.
In this world, you really only have one thing, and that is your word. Without it, you have nothing.