Profit depends on your costs. If you have monthly costs of $5 for renting a VPS where your NEM node is running, then you could be profitable by harvesting with 500k of NEM. But it also depends on your importance. Someone with a smaller amount of XEM and a high importance can be as successfully as someone with a higher amount of XEM and a lower importance.
and nobody in polo..im alone troll for xem..fuk

12K is not enough to harvest many blocks...

How much XEM is recommended in order for harvesting to be slightly profitable? I think a guide to how to harvest XEM should be written and posted online to encourage people to be proactive in the network.