Cost of mining is now close to 600$.
You must not be very good at mining then.
I don't mine but I have buddies who do. If your cost of mining is $600/BTC you might as well hang it up now because other, much smarter, people have figured out ways to mine at a much lower cost of production than you.
You are really losing $100 per bitcoin you mine? That is like beating your head against a wall. Stop that.