When a buyer proposes an offer, you can accept or deny it or make a counteroffer stating what can change for it to be acceptable. It’s then up to the buyer to accept or refuse your counteroffer or make another counteroffer to the new terms.
How to Handle Offers
Negotiation isn’t just about price. The contract has dozens of terms that can be negotiated that have an associated cost. Make sure you understand the buyer’s position and motivation so when they ask you for a concession you are understand what you can demand in return.