If you are serious and have finance ready to go, do this.
Put an offer in writing as your last and final offer of say $375k. or $365k, its up to you.
Then you have to tell them why you are making such a low offer. You have to sell them on your offer. You need the agent to go into bat for you. A written offer is very powerful to an agent as he/she can take it and show the vendor "this is what the market is saying blah blah" they love that vendor conditioning power.
Write "my offer is made on the basis of":
Current market conditions.......explain how crap they are.
Comparable sales, if they are really bad, list them.
Condition of property...pick on anything you can think about the house, the street, the area....etc
You get the idea...build your case for such a low offer and the agent will present it to the vendor and go into bat for it.
Also, make it time sensitive. eg: "this offer is valid for 48 hours" or whatever.
Tell them you are also looking at other properties and will make a decision very soon.
This has worked for me lots of times and should be good for you in this current market.
Its much better then just ringing the agent and saying "$365k is my offer"
If they knock you back, you can always come back later. As you say, it probably wont sell in the meantime (what ever you do, don't believe there is another offer in this market) and as you say, you have other properties to look at.
original price of $495, dropped to $419,
your counter offer $365 ,
new offer is $409,
why not take in between $387 or $390.....
Ill bet they will seriously consider $390...
I think it said in another thread, "be prepared to walk way" to get the best price!