Hello, my name is ***** ***** it is my pleasure to assist you with your question today.
This could indeed be a legally binding agreement. A legal contract can be formed simply through the actions and deliberations of the parties involved in it. In common contract law a contract is formed when there is an offer, acceptance and consideration. In your case there was an offer to buy the goods at a specific price, this was subsequently accepted by you and you provided consideration by acting on that and withdrawing the goods from sale. Therefore, you are able to hold the other party to the original offer.
Thank you for prompt answer. Nigel
you are most welcome