@Joaquin K. I would recommend searching the NARCA directory to find a law firm that can help you. They will be able to give you advice about what collection methods are available in California too. PM me if you want a link to the directory.
The amount charged can vary widely depending on the quality of information you are able to provide, quality of tenant, and the amount you are owed. If you don't know where the former tenant is now, the balances are small, and the former tenant likely has no assets, it will be expensive to collect on the debt because it will take a lot of effort, so the charge may be closer to 60%. If you know where the former tenant lives and works now, they owe a lot of money, and you know they have assets, it should be easier to collect, so the amount charged should come down.
