After completing the first UP mission and recruiting Ewan, talk to him about the 
Winch challenge. After completing level 3 on this challenge, bet the maximum 
amount of money. Even though you have already done this, the height does not 
raise. Therefore you can continue betting at the maximum amount. After 
approximately four times (depending on how much you start with), you should have 
about $7.0 million. Continue from here to get the maximum wager amount to $5.0 
million (when you have about $14.0 million in funds). Repeat this as many times 
as desired. Additionally, when you get the maximum betting level on the Winch 
challenge, keep going until you get to approximately $100 million. The minimum 
bet will now also be $5 million. If you continue from there, the minimum will 
actually grow higher than the maximum and allow for even more money. However, 
once the minimum goes beyond $5 million, there is no way you can raise or lower 
the bet because it is higher than the maximum, but it is still the minimum. 
Note: To save time in the Winch challenge, use stackable items from outside of 
your stronghold. For example, try the gas canisters across the road (or for 
something less volatile, use the shipping containers directly across the lake 
behind your house). Items used from outside of your stronghold stay in the exact 
location you put them until you quit your game, giving you a prepared stack 
height the next time around. Two or three attempts may be required to gather the 
items, but it is well worth it, as once done it requires only seconds to win the 
challenge.