Free caps and slave collar hint
During the "Strictly Business" quest, capture Susan Lancaster and receive your reward. Afterward, speak with her in the slave quarters part of Paradise Falls. Note: One of the slaver's keys is required to access the slaves quarters; pickpocket one. After entering the slave quarters, speak with Susan and when she asks for help, select the option "You're a slave. Deal with it." Return to Grouse to collect your reward again. Grouse will think that you captured her again. You can repeat this for 250 caps and a slave collar each time.