The proper procedure is to enlist a Realtor, (a Buyer's Agent is free to you),
The Agent does a CMA to determine the Market Value.
Together, you make up an OFFER,
you include Contingencies for INSPECTION, APPRAISAL and LOAN;
so that you are protected.
Even if the property is sold As-Is, you can back out because of the Contingencies.
If you do not have CONTINGENCIES, and you have signed a CONTRACT; you are buying the house!
Just one of the reasons for using a Realtor.