I have a suggestion for newer players that have a low level Austin but still need coins. Try out Stage 1 Challenge 3. The presence of a graveyard produces a nearly unlimited source of easy to kill zombies. With Austin’s new handgun, his rate of fire, and easy to farm zombies, you can make, at a minimum, 900 coins. If you manage to survive through the end, you can cash in at anywhere from 1000 to 1300+ coins in a single run. My setup includes red or blue barrels to control pooches, a generator, medic or a first aid kit, Austin, and Marine. Enjoy!!