Unless your are in an area with a market bubble, where everyone is buying, FSBO doesn't make sense in most cases.
The reality is:
1. You get less traffic to a FSBO
2. Those who do come are intelligent enough to know that you are saving the commission and will negotiate price based on that, eliminating your hoped for savings.
3. How long will you let it sit because FSBO's stay on market much longer than agent listed homes.
4. The longer your on the market, the more pressure you feel to lower the price, a good agent will price it right and know the prices to get a sale within your timeframe.