A really easy way to get the badge: The default map and this : "This might be faster on the "nightmare" difficulty setting. Disabling demons, collision and friendly fire in the options menu is allowed. " but use the rocet launcher to simply spam the doorways, if they somehow manage to escape that just circle around them with barrels.
Okay, wanderer. Hope you can deal with some rogues, right? We'll pay you 100 gp. - No
Okay, wanderer. Hope you can deal with some rogues, right? We'll pay you 3600 gp.
These guys have really good negotiation skills!