In order to get another view on the valuation of some gold explorers/miners, have a look at the latest Prodigy Gold presentation:
http://prodigygold.com/_resources/presentations/prodigy_presentation_20120203.pdf
Page 19 shows a table, where Probe is included as the 4th lowest valued explorer based on Enterprise Value per ounce in the ground.
All companies in the lower third sector seem to be grossly undervalued, but you have to look at their individual "circumstances", because some of the low valuations could be justified based on (difficult) location, missing infrastructure, not open-pittable, high operating or mining costs etc.
FANTOMAS