there was an audio interview with mike hill a while back explaining what a junior gold exploration company like Gemini does which find a mine, explore it, drill it and get estimated reserves and then one of the big boys comes in an offers $$$$.
but one thing a company will consider is the price of gold if it keeps going the way it's going they might reconsider and become a producer which will take alot longer maybe like 3-4 years to see large amounts of producing. whereas if you want to get bought out it'll be about 1-3 years depending on how quick you move and if you can secure proper financing.