... buy a gold property!
Most of Klondike claims are already profitable at a gold price of about 800 - 1,000 US $ (and today the price is $ more than 1,300!).
The average content of a decent proven claim should vary between 100 to more than 500 oz (for each one). The cost of a mining operation can vary between a minimum of $ 100,000 - $ 300,000 (for a small 'two guys' operation), up to 20 time or more for an industrial production.
The price of a claim also increases when the price of gold goes up, and that's could already be a good reason to invest on gold properties.
...but the most important part is: the price of gold will most probably keep increasing in the very next future!