Typically, the selling expenses are paid by the short sale lender.
However, and depending who the lender is, and what type of property you have....
If you have an HOA and you've been delinquent, the HOA can file a lien against the property and even file for foreclosure. This is why we encourage homeowners to keep up with their HOA payments because most short sale banks won't pay for HOA fees and fines.
If the buyer is using an FHA loan to buy your property, there are some stringent requirements. You may be asked to fix certain things before the loan could be granted.
Your buyer may ask for some repairs. If they are minor, you may consider acceding to the request to keep the file moving forward.
You should also maintain the insurance on your property, otherwise the bank will get a force play insurance and bill you.
It really all depends on the type of property, how much you owe and to whom,
Remember, you are asking the bank to forgive your loan....during this process, you are applying to see if you qualify. Not all people who apply are approved.