BRM is severely undervalued due to their lack of rail infrastructure. Soon as BRM gets a rail agreement, their market cap will be 3-5x their current (no joke).
DMA will go through the same process, so I don't see 500$m as being out of question for this little miner.
Given they still need to finish proving up their resource and get through their PFS/DFS, it is still got to be worth more then $31m!