You are assuming a lot here.  Not everyone's pricing works the way yours does.  We do not bill by years.  We bill by number of OWNERS.  We don't even offer a 20 year search. 

So what's the difference between a 1 owner and a full search?  If it's 40 years, you're saying there's no difference.  But that's a lot more work and a lot more books to run thru.  You can't just find the vesting deed.  You have to work forward from 40 years ago.  So again, what's the difference?  Why don't you charge the same for a full search as you do for a 1 owner?