Gold costs

Source: FT
The recent gold price fall means more trouble ahead for gold miners. The all-inclusive cost to produce gold is about $1,000. If gold prices fall below $1,000, some gold reserves (assets) would be unprofitable to recover and need to be written down, putting pressure on the more indebted miners.

http://www.ft.com/cms/s/3/ffc1faba-3cdd-11e5-bbd1-b37bc06f590c.html#ixzz3iTxVT8PG
Gold cannot fall forever. Even so, listed gold miners should at some point be cheap. One early buy signal is when it costs less to buy mines on the stock market than to build them. Building a gold mine from scratch can be measured, crudely, by the cost of the investment (including debt) an ounce of gold produced. An average new mine would cost $2,500 an ounce of annual output, estimates RBC. Yet the larger listed gold miners still have an average enterprise value to production of $3,600.