In Konquest mode, koins will always be appearing right infront of you. These are but the tip of the iceberg. Go into people's houses for masses of koins, like 50 or 60 at a time, as opposed to 10 or 12.

Red Chests are an excellent source of koins. They hold no less than 200 at a time, and are fairly common.
Chess mode is an easy win, too.

If you're good at Kombat, your chess skills are about as useful as a Lava Lamp to a republican. You can always beat your opponent, even if he hits you first. You just have slightly less health. Take the leader for a nice fatality demo.