What a listing really costs
The fee is the visible cost. The real cost is everything after it: writing the ad, answering enquiries that go nowhere, scheduling inspections around your week, having strangers drive your car, and negotiating with people whose opening move is to find a reason to pay less. Then there is holding cost. Every week the car sits unsold, you are paying registration, insurance and depreciation on an asset you have decided you no longer want.
What an instant offer really costs
Money, generally. A dealer buying at wholesale is taking on the reconditioning, the warranty exposure, the holding cost and the risk that it does not sell quickly. That gap is the price of certainty and speed. Whether it is worth it depends entirely on how you value your time and how much you dislike the process.
Which cars suit which
List it privately if the car is in strong demand, presents well, has complete history and you have the patience. Enthusiast cars, well specified late model examples and anything with a devoted following reward the effort.
Take offers if the car is ordinary, high kilometre, has damage or a service gap, has finance owing, or you simply need it gone. These are exactly the cars that sit longest on listing sites and get negotiated hardest by private buyers.
You can do both, in the right order
Get written offers first, because they are free and take a minute. If you list afterwards, you now have a floor and a deadline: if the listing has not beaten your offer in three weeks, take the offer. That is a much better position than listing with no reference point and slowly dropping the price until something happens.