I asked the same question this time last year and didn't get much advice - apart from the helpful suggestion that school term times are busiest.
We bought in mid-December, and there was virtually no-one on the cold streets of Dublin, so we snapped up a bargain - but then again there was very little supply around then, for that matter...
But I think that the best advice I've heard, when it comes to such things, is just to do it when you're ready - because trying to time the market is a mug's game... (Especially these days!)
Best of luck!