There are so many oils listed on this site that I learn alot. But where can I go to compare current prices? I read alot here about Mobil1 to Amsoil and Red Line and Schaeffer and would like to compare prices without talking to some pain in the neck sales rep or getting on some mailing list. Anyone know some current prices on the oils not in the stores like walmart? I can not find royal purple,schaeffers,cenpeco or any specialty companys in the stores. Thanks