On my 98 E320, is there a difference between the OEM spark plugs (F8DPP332) cost from $8.46 to$12.35 depending on seller vs. +4 platinum (Bosch 4418) which cost about $5.99 or Bosch Platinum 2 (Bosch 4301) which cost about $3.79 each at Wal-Mart. Thanks