I didn't do any particular calculation, the number was just based on my experience and on numbers from other people from slack.
There was a solo mining guy with a 100MHs with an average rate of 1-3 blocks per day, some other guy had 150MHs with 3-5 blocks per day.
But the diff jumps a lot, so during last two weeks it was even less than this. Right now the diff is 280, but a few hours ago it was 900 (!!!).

You can check current Prime (CPU) and Hash (GPU) difficulty here:
http://nexusoft.io/platform/ExplorerParticular calculation 1-2 blocks per day speed 200MHs(((
Yeah, with a current diff it started to be not profitable anymore.

And with CPU mining, it gets worse as well. One month ago, I could mine with 800pps around 10 nxs per day, now I can barely do 5 nxs (I'm talking about pool mining, I wouldn't solo mine with that low hashrate).
Also, with the current price drop, nexus mining is only for true enthusiasts and believers!
