What is the cost to create Materialized View log

Recently I ran DBMS_ADVISOR.TUNE_MVIEW and it gives me several lines to

CREATE MATERIALIZED VIEW LOG ON "MYSCHEMA"."COMPANY" WITH ROWID   
CREATE MATERIALIZED VIEW LOG ON "MYSCHEMA"."BOARD" WITH ROWID  
....
CREATE MATERIALIZED VIEW LOG ON "MYSCHEMA"."CONTROL" WITH ROWID  

and the script to create materialized view is pretty simple with multiple joins and conditions:

  CREATE MATERIALIZED VIEW V_SUMBAL_AMT 
  BUILD IMMEDIATE REFRESH FAST START WITH (sysdate) NEXT (sysdate+1*60/(60*60*24)) WITH rowid AS  
  SELECT sb.id as id,  
  SUM(c.OPEN_DAY) as open_day, sum(c.OPEN_NIGHT) as open_night, 
  SUM(c.CLOS_DAY) as clos_day, sum(c.CLOS_UNV) as clos_night  
  FROM company c  
  join board b on c.company_id = b.id  
  join summaryBoard sb on sb.id = b.summary_id  
  join control cl on cl.id = c.control_id  
  where cl.ignored <> 1 and c.control_id IN (SELECT cm.control_id from control_manager cm where cm.manager_id = b.manager_id)
  GROUP BY sb.id  

I know it looks a little messy, just give an idea about how the view looks like. My question is shall I follow the instruction to create view log? And what is the cost if the dba will never manager the view log so what is the cost and impact to the database?