To get camo's you need to play the slot machine i think but it costs a lot and takes a long time to get all the camo's
Not really, because of how little stuff there is worth buying in the shop, you might as well waste it all in the slots.
If you don't have enough money to buy something, just start a mission you will never finish and play until you have enough money, and then quit before you finish, and the shop will still have the same items.
