I agree.  Frequently, it is best to attempt to buy at the lowest possible amount, and when ALL of the exchanges appear to be going down rapidly, it makes one wonder how far down the price is  going to go.

On the other hand, as you suggested, if you have a little more Fiat to spare, then you may err on the side of investing a little more as the price is going down.. in order to NOT get left behind.  Though since we have been in this price range (fairly recently), in the last couple of weeks, several of us have already bought at around these prices.  I am thinking to buy around $420, now.... though I am NOT very confident that the prices are going to go much lower than that --- currently bouncing off to $433 from $425- but I will save some fiat, just in case we go to $400 or lower.