Rabbi is right on the money (no pun intended).
If you go MLS, even with the $250 no-rep service you mentioned, you are likely going to have to sign a contract that you will pay X commission to the buyers' agent as part of the listing deal (anything going into MLS is a listing agreement whether you have representation or not).
If you go straight FSBO, don't be surprised if an agent calls as say, "I have someone that is interested in your house. Would you be willing to pay X commission if I brought you a buyer." If you say yes, they will show up on your doorstep with some kind of simplified commission or compensation form. The only caveat is to make sure you are obligated to pay them a commission for a specified buyer, not buyers in general. If the buyer is not specifically stated on the form then you are signing a blanket commission agreement with them. In other words, no matter who they bring you will be legally obligated to compensate them. Some shady agents use this tactic to cover any and everyone they meet. More honorable agents will have a specific buying party listed in the compensation agreement.
As Rabbi said, you are only obligated to pay a commission if you have specifically signed an agreement for compensation. Just understand that the agent is representing they buyer's interests, not yours.
I would be surprised if an agent just showed up with clients in tow. Any agent worth his paycheck will have done his homework (contacted you and gotten a signed commission agreement) before letting his clients know that your house even exists.
Now some reality checks...
I don't know what the market is like in Ft. Lauderdale, but 300K worth of house is not a pittance in anyone's book. Chances are the people with that kind of money don't have the time to drive around looking for a home that just happens to be for sale. In all probability they will call a real estate agent and say "Find me a home." As a FSBO you are cutting yourself completely out of the majority of the market unless you intend to pay some kind of buyer's agent commission.
There is a reason that the national average percentage of FSBO to MLS hovers in the 15-18% range. Money. Your money. As in the amount of money in your pocket when you leave the title company. The more people that know about your home the more chance of getting a price in line with comparable properties.
For example, in the Lubbock market MLS listed properties sell for an average of 4.5% more than comparable FSBO properties, and they do so in approximately half the time (45 days vs 90). The average home here hovers in the 120K range and tax, insurance, and interest expenses amount to roughly 3.5% per month. The math breaks down like this
MLS
Sale price - $120,000
Time on market - 45 days (1.5 months)
Our commission - 6%
Price $120,000
Less commission -$7,200
Less 1.5 months tax/insurance/interest -$1,300
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Total Deposit to Hip National Bank $111,500
FSBO
Sale price - $114,600
Time on market - 90 days (3 months)
Commission - 0$
Price $114,600
Less commission -$0
Less 3 months tax/insurance/interest -$2600
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Total Deposit to Hip National Bank $112,000
$500 difference.
Now the question become one of how much you expect to spend on marketing (ads, flyers, etc) and how much your time is worth (phone calls, tours, negotiations). There is also the aspect of how the time difference is going to affect your move, and any income or living expense considerations in your new location. Figure on spending at least a bill or two on ads and flyers. That leaves $300 for time considerations. Figure you spend one weekend (Fri-Sun) holding an open house at 4 hours a day, plus another 4-5 hours negotiating and running back and forth to the title company. That's 16-17 hours of your time in the transaction. You have just established that your time is worth about $18 per hour - that's what you're saving by doing it yourself.
Don't think I'm telling you not to try selling it yourself. Far from it. Many people sell their home on their own every year. Just understand what you're getting into. You only save money if it sells for the same amount, and in the same time frame, as a similar home sold via MLS. The odds are roughly 80% against.
Whatever you do, don't fall into the thinking that you can price your house up hping someone will just come in a make an offer. The stats are unequivocal in this respect. Houses priced closer to their estimated market value tend to sell faster, and for higher prices, than houses priced significantly over market value. In fact, if you look at the percentage under market value for sold price vs. the percentage over market value for original asking price, they mirror. In other words, if a house is priced 5% over market, chances are it will eventually sell for 5% under market. The only exception to this is a very hot market where there are few, if any, homes like yours available for purchase.
Brad