I'm guessing the buyer bought extended owner title insurance rather than the regular owner title insurance which is less expensive. The "per rate filing" just indicates that the charge for extended coverage is determined by a filed rate, likely with the state insurance department.
I'll further guess that the buyer didn't get a moment in which to choose whether or not to purchase the extended coverage. The "per rate filing" lingo makes me think the party who added it might want to make it all look official so the consumer doesn't ask questions. That could just be cynicism on my part, though, because it really kills me how many title insurance agents place consumers in higher priced coverage without asking, "Mother, may I?"
Conversely, we have the entire other school of thought in which a title insurance agent never offers owner coverage and just slips a little waiver under the consumer's pen at closing. All this under the guise of making their pricing look more competitive so they get more referrals from lenders and real estate agents - ignoring the big but...... BUT - the consumer doesn't know THEY HAVE ABSOLUTELY NO COVERAGE HAVING ONLY PAID FOR A LOAN POLICY.
So, over pay or under pay, I don't care as long as the consumer gets to make an informed decision.
Let the consumer, the one whose money is in play make the decision, eh?