My suggestion is, you should add a place where you can fight in a championship or something, in an arena. There are also some merchants who will sell weapons and ammos. A training camp or something will also be available.
About the championship thingy, you will need to pay to enter the championship. you will be given only a type of weapon for each match. To win, you must knock out the opponent before the time limit. After winning the championship, you will get a lot of scrap/items.
Okay, I think that's all for now.