It depends on how tight the rental market is and how low the vacancy rate in your neighborhood of choice. Typical fees for leasing brokers are 1 month’s rent. Sometimes they’ll go down to 1/2 month’s rent. Depending on the type of apartment that you’re looking for, this can be made up for by the owner providing rental incentives such as 1 month’s free rent. Everything is a negotiation, it definitely doesn’t hurt to ask. I’m based in NY, but I believe the Los Angeles rental scene is similar to NYC.