There's an American saying - if you're getting no viewers drop the price by 10%, viewings and no offers drop by 5% (not saying it's god advice,just stuck in my mind!)
(Please don't be offended by this next bit, as this is just how I view the world and may not be representative!)
Hypothetically, I like your house but feel it's overpriced. I looked at the 449k and am automatically knocking 10% off in my head, but decided it wasn't worth asking price minus 10%, (i.e. 400k). I might think it's worth 375k but don't bother putting in an offer as I expect you to reject.
I keep your house on my RM save list to see if it sells or drops.
If you drop the asking price and the drop is 10k then that completely puts me off - this person is just messing about and clearly wouldn't be open to offers anyway as she's no flexibility. To be honest I'd stay at 449k rather than do that.
If you drop and the drop is ~20-25k then this is broadly what I expect, a drop of 5%. That might mean I'm now tempted to place an offer of below 400. It also means that others with a max price on Rightmove set at 425 now see the house.
If you drop to around 400k (i.e. 10%) then this is a more serious drop and would get my offer plus bring in further interest (who actually may offer more than me anyway).
All of the above is based on the areas I'm looking at where much of the pricing is over 2007 levels. If you're getting viewings and yours isn't overpriced vs nearby similar sales then I'd probably drop to 425k - diff RM search category, a drop of slightly over 5% looking reasonably motivated.
^^ bit rambly. Should be in bed no doubt.