Some contracts of sale provide that if the closing does not take place due to the fault of the seller, the seller reimburses you for mortgage and title fees-- read your contract--- better yet, have your attorney read ALL documents you signed to assess which expenses may be recouped. It is not an all or nothing affair.
Any further questions, you can call me 646-714-2720.
The seller can't close would mean they are in breach of contract unless there was some contingency that was part of the original agreement.
The appraisal is done so that is an expense, any other inspections, and the rate lock fees are all damages to you by the seller breaching unless there are mitigating circumstances.