I would never again use a full service 6% broker. Never.
Sorry you feel that way, all my past clients write me love letters.
Over the past 25 years, we have sold all 5 of our homes FSBO, and saved thousands and thousands (and thousands!) of dollars. Never had a problem ...it is amazingly simple, you just need a good title company or attorney, who will even write the contract for you! Nowadays, you can easily create your own market analysis with the help of the internet, so no worry about being over/underpriced.
If everyone tried it just once, no one would EVER list with a realtor.
You are incorrect here. The broker is not charging you 6%. The listing agent is taking up to 3% and the buyer's agent is taking 3%. Some listing agents will do a 4.5% listing which means that they are only taking 1.5% of the transaction.
The realtors are adding tens of thousands of dollars to the cost of the house purchase though. Agents on both sides of the transaction can add value to their client but the practice of sellers having to pay for the buyer's rep is garbage.