Signing a listing agreement gives the real estate brokerage the right to market your home for sale. If you are not truly prepared to sell your home you should let your broker know right away and ask them to prepare the appropriate paperwork to cancel the listing. You don’t want to put would-be buyers through an emotional roller coaster ride if you really don’t want to sell. As for costs, unless there is something clearly stipulated in the contract, you should not have to incur costs. Your realtor may have spent some money and a lot of time preparing the listing for the open market, so just be aware of that and try to be respectful. At the end of the day, nobody can force you to sell.