From the quarterly MD&A, Total shares plus restricted stock...

From the quarterly MD&A, Total shares plus restricted stock units is 288.209 + 1.736 = 289.945m
Multiply this by share price to give market cap about $A1300m at $4.48.
This is probably good enough, although should be adjusted for options in the money, which adds about $15 m.

Is this overvalued or undervalued?
At current cash costs seems reasonable, but they are spending a lot each quarter on sustaining capital- last quarter about $44m. This is counted as investment by the company, and takes up most of the profit at the moment.