You should always write an offer if you want to do so, even if it’s a low-ball, regardless of what the agent tells you.

The seller’s agent is obligated by fiduciary duty to present all offers to the seller.

They may not respond and let your offer expire. But in this declining market the sellers will kick themselves over and over again when they look back and see your offer in writing. When the house eventually sells for less than your offer, you’ll have the satisfaction of knowing they’ll still be thinking of you for some time. 🙂