In my experience, title searches are always a "last minute" thing. Buyer is pre-approved for a loan, an offer is accepted and the buyer calls the bank to get the check. The bank starts their appraisal process, title search, etc. That's when issues pop up.
Until a sale is "pending" there's nothing to "title search" against, assuming the seller has every reason to believe that they own the property they are selling. I'm pretty sure most sellers don't pay to have a title search done prior to putting the house up for sale.