You as the owner can negotiate any type of fee scale you want.
A few things to bear in mind:
1. I don't know your market, so this is a general comment - most markets are buyer's markets, meaning there is more inventory than buyers. Many markets are declining (meaning due to the recent changes in lending requirements there are fewer qualified buyers now than prior to September. So less demand, increasing inventory, what happens to price?
2. According to the California Association of Realtors Buyer survey for 2007, 90% of the time the buyer sees the home they purchase with an agent. Why is that statistic important to you? By selling the home by owner, without professional representation, you effectively exclude 90% of the buyers.
3. Assuming your market is as stated, that means that if if LISTED homes are having a hard time selling, a home sold by owner is less likely to sell. So if the market is declining, it is likely your home will be worth less in the future. So "testing the waters" as an unrepresented seller may cost you more than you think.
4. Over 85% of owners selling without professional represenation eventually list with an agent.
5. According to the National Association of Realtors 2006 Seller Survey, " the typical FSBO home sold for $187,200 compared to $247,000 for agent-assisted home sales"
So, to sell your home on your own is up to you. Less than 10% of homes sold in the US are sold "directly". However, if that means making less NET profit, why on earth would you sell on your own? I suggest interviewing some Realtors, look at your NET, after expenses of selling, and then you make the call.