Never forget rule #1 in sales. A product is worth exactly what a buyer will pay for it and not $.01 more. In other words, $400.00 is high to you, perhaps because you don't want it badly enough. Somebody else might. The seller listed it at $400.00 but that doesn't mean that is what he expects to get for it.
I sold a bike last night for what I asked. But that was because I put an eminently fair price on it initially. I had lots of prospective buyers. I could have listed it for what I actually believed it was worth and waited a few weeks to test the waters. I've done that before and sometimes the right buyer comes along and sometimes not.
That bike looks very nice. It is 8 speed, so that is automatically cause some to pass it by. Shame, because Shimano 8 speed groups were some very nice-shifting, reliable components and you can still get replacement components fairly easily should something break.
If you are interested, really interested in the bike, offer $300.00 and see what happens. If $300.00 still seems high to you, then you obviously don't want that bike and could probably do much better with your $300.00 as long as you are patient. Timing is everything and believe me, the second you buy a bike off of Craigslist, a better one for the same price will appear almost instantaneously. That's just the way it goes. Good luck in your search.