Dead Rising 3

Earning Zenny is a natural part of this DLC. You will get Zenny bonuses for coming in 1st place in a round for specials used, zombies killed, overall points, perfect bonuses, etc. You also generally get a ton of zenny for completing the rounds themselves, and there are bonus chests, barrels and crates containing zenny in the rounds as well. I would usually end a district while playing solo with anything from 15-25k Zenny, so this achievement will not be hard to get by just playing through the DLC. To put it in perspective, by the time I got all of the achievements and bought all the costumes, I still had about 200K left over.