You could offer 20% below,Just use a letter of intent.It is one page and non binding .Make sure you mention the falling market and your concerns about getting hurt, perhaps in a cover letter to the agent. Go away for a couple of months and if the house is still on the market they probably will have dropped the price a little. If it plays out that way go back and ask them what they think about your offer again. You can do this on several house to improve your odds. I don’t know that many people who have this kind of discipline but I have done it and will do it again. It satisfies the itch to be in the market without totally ruining the fact that time is on your side. If the market really falls just start a new round of “lowballs”.
Disclaimer: This stategy is not for everybody.
Best wishes