It is not a matter of how much you think you should pay, but rather a matter of how much your client was actually required to pay as a result of the lien or mortgage that was not included in the abstract.

If you were hired to perform a search which should have disclosed all liens and mortgages within the scope of the search, you could be sued for negligence or contract breach for failing to include the lien or mortgage within the abstract. If your contract with your client provided for your client's recovery of attorney's fees, you could be held liable for these expenses also.

Therefore, make certain that you carry enough e&o insurance to cover the claim.Also review your policy to see if your attorney's fees are deducted from it, and thereby potentially reduce the amount of funds available to pay the claim if you lose. You are personally liable for anything in excess of the limits of your policy

Also make certain that you are organized and operating your business as a corporation or LLC to further limit your liability.