I know I am gonna get hammered for this, but we rarely charge more for a complex search.  At the same time we never discount for an easy search.  These two used to balance out, but with most of the easy searches being processed online & through title plants now, ALL thwe searches we get tend to be complex.

Our company is fairly new (less than 10 yrs) and operates only in 3 major metropolitan areas where the competition is remarkable (L.A., S.F. & N.Y.)  That means that by the time a search gets to us the client has probably tried just about everything else :-) 

The one recourse we have been using more frequently is the research fee.  If a search turns into a monster we estimate the number of hours and stop work until the client approves the hourly rate or goes elsewhere.  Of course we then have to fight to get the client to actually PAY the research fee - we try to get approval in writing before doing the work which helps a little.

As I close out last year I am able to see the deadbeats and I gotta admit, it's not so bad for us.  Only about 2% of our invoices go past 90 days, and far less than 1% actually go unpaid.  Maybe we are just lucky.