I have just run an estimated execution plan and there is one step that is showing an estimated cost of 92029%!
The procedure is intended to delete data from a table based on the values in one date column - if its over 3months old then delete it. The whole query cost is 100% but the clustered index delete is 92029%. In the XML version the %cost is not findable .. :-/
SQL 2005 Std edition 64 bit sp3