The buyer has made an offernow what?
It is up to your agent to present you the offer and give you recommendations. A seller can do one of three things. They can accept the offer as is or put together a counter offer or do nothing and let the offer die at expiration. (Offers have expirations dates and times. If the seller does nothing until after the expiration, the purchase agreement is null and void.) Your agent will recommend to you what is in your best interests to get the deal done.