Congrats on closing the refi. Hopefully you got some nice equity out or a better rate.
Closing costs generally average around 2-3% of the sales price as a general rule of thumb, but they can vary based on any number of factors. As a Seller, your closing costs will be made up mostly of realtor commissions, attorney fees, transfer tax, some recording fees, title release and/or mortgage payoff fees, and potentially some other miscellaneous items that could be unique to your deal specifically (Seller concessions/credits).