I believe the cheaper ones are, yes. However, what value does a broker add that you can't do yourself?
I believe strongly in brokers. A while back, I had an accident all by myself. Damage seemed minor so I thought I'd sort it out myself and left it for a while, but when I went to go get a quote, it was over R20k. I was past the deadline to submit the claim, but thought I would take a chance. The insurer originally denied the claim, but the broker fought my case and the claim went through.
If I had gone direct to the insurance, they would have just denied the claim, but because the broker has so many clients with them, they have bargaining power with the insurance company.
On top of this, my broker also adjusts the insured values of all my items annually (checking list prices for my cars and typically increasing household contents by inflation) and email me a confirmation of what the new values in case I want to adjust them myself.
There are usually a few other perks and value adds, but those are really the main reasons why I would never go direct. I once got a quote from Outsurance and was shocked at how expensive they were and how high the excess was.