Assignee Buyer backs out - deposit

[Terry Royce]

I had a property assigned to an buyer. The property was condemned, but the city would allow it to be rehabed.
The buyer decided that their costs were going to be higher than expected.

The contract states that the deposit is NON Refundable, and only refundable if Seller does not perform, and/or good and marketable title cannot be transfered.
It also states that Assignee agrees to buy property in As-Is, Where-Is condition and that assignor makes as to condition, present, or future value. Assigne is responsible for performing all due diligence necessary 8. Both parties agree that if Assignee fails to perform any of the covenants of this contract, all deposits paid pursuant to this contract by Assignee, shall be retained by the Assignor as consideration for the execution of this contract and as agreed liquidated damages in full settlement of any claims for damages.

So the buyer has requested a release of his deposit from the title co. Should I release the deposit in order to save a relationship with a buyer? Should I only do it if I line another buyer up? Or should I keep it either way?

This is the first time I've had a buyer back out.

Input appreciated.