You are not required to pay a 6% commission. In California, as in any state, the amount to be paid is negotiable. I have very often worked for people on a consulting fee basis based on the estimated amount of time they are paying for my expertise.
If you have the expertise and understand all the legal ramifications and risks, do it yourself. But you have nothing to lose and likely something to gain by giving many brokers an open listing and agree to pay a fee above the net price you are seeking. You will have many more people working for you while still having the ability to sell yourself.
In some markets and areas I agree, you might need a realtor. Where I am at, you don’t need one to sell your place. Word of mouth sells the house in hours. A nice home in my area will last a matter of hours on the “market” right now. My son just mentioned he was going to be ready to sell on facebook and had three people contact him almost immediately. Sold it to the first person who responded the next day basically after they came to look at it. If you know you have a clean title and there are no issues, I just don’t see the need. With all of the FSBO websites/publications in areas. Also around here, realtors don’t normally negotiate their rate at all. Having had to deal with them for 18 years doing mortgages, I found them to be a royal pain in the rear, didn’t do anything and collected a nice commission check for the work I did.