Easy Experience And Weapon Proficiency:
Use the following trick to get easy experience and weapon proficiencies, as well as more weapons and cash by selling loot from all the dead enemies. For this to work, make sure you do not kill everyone. Leave one enemy alive (preferably the little ones), otherwise the quest ends. Also, do not die. You will lose lots of your hard earned money. Exit out (the game saves automatically) after killing almost all of the enemies and collecting all the sellable items desired. Reload your game and re-rampage in the arena. When you exit, the game saves all your information. Reload your game. Once you are in "the middle of nowhere" you will eventually get a Thunderdome/Arena type quest called "Circle Of Slaughter". You can go into the game, enter the arena, and slaughter everyone except one enemy. Note: There are three rounds, with the last one called" Final Round". Do not finish it if you want to repeat your work. You will earn easy experience, weapons proficiency, find nice loot, and money from selling all the items you do not want.