One of the main reasons a for sale by owner will not want to list with a real estate agent is because 1. they had a bad experience with a real estate agent, or 2. they are trying to save money.
Every profession has a handful of professionals in their field that are not so professional. Do not let one bad experience with one individual characterize everyone in the entire field. The first step into making sure you are working with a professional in real estate is to make sure you are working with a Realtor®. Not all real estate agents are Realtors®. A Realtor® will practice real estate and hold themselves to a higher ethical standard than a real estate agent would. Another tip is to make sure that you interview a few agents to make sure you are going to get along with whom you choose to work with. Just because your friend may have referred you to an agent does not mean you will get along with this particular individual. Make sure you interview a few different agents before choosing one.
Trying to save some money on the sale of your house by not using an agent is ineffective. According to the National Association of Realtors, "The typical FSBO home sold for $200,000 compared to $265,500 for agent-assisted home sales."
The main factor for a FSBO selling their house lower then a Realtor is simple...
The way to drive price is supply & demand. The more demand for something, the higher the price will rise. A Realtor will be able to market your home to thousands of of people, using a hand full of different tools. Whereas, a for sale by owner will only have a few marketing tools to expose their home to a few hundred people... Therefore, the more buyers you can market to, the demand for your property will increase causing the price to rise.
In conclusion, listing your home for sale with a professional that you have interviewed and chosen will end up putting more money into your pocket, more time into your pocket, and create for a lot smoother transaction.