Price was as low as 0.0000025 a couple of days ago. That could be the "base" value for now.
I think the upside spikes are not all manipulation, I have sold a few thousand NXT for about 0.0000088 some days ago and I have not bought them myself
We should aim to redistribute more NXT. Another exchange would be helpful. Cryptsy seems not to be adding coins, and for the "great exchanges" it's far too early. But what about http://coins-e.com or http://coinex.pw?