Buyers typically discount FSBO's by the amount of prevailing commissions anyway.
Example: FSBO is on the market for $400,000. Area comps have sold through Realtors for $380,000. Typical commission over the past year has been 5%. I'm a buyer. What's my offer?
The net price to the sellers who used Realtors was $361,000 ($380,000 less 5% commission).
Conclusion: I want to pay $361,000 max, so my offer would be $330,000-$340,000.
The FSBO will argue: "That offer is ridiculous, the neighbors sold for $380,000. I'll take $380,000 period, no less. See what is happening? The seller wants to be paid the 5% commission he is NOT PAYING to the Realtor.
So you can go it alone, but buyers are not dumb these days. Buyers know you are not paying a commission and will adjust their offer downward to reflect the commission savings. So you lose valuable Internet exposure and limit your pool of buyers with no reward at all. The more buyers, the better chance of selling at the highest price.