anvil,

I haven't bought any from ATCO or SP, but a lot of my friends who owns mitsu cars say that ATCO is cheaper compared to EL-Dorado. SP I think is also cheaper compared to EL-Dorado. Is the difference in price that big, I don't know.

I buy my "important" parts sa El-Dorado dahil walking distance lang sa bahay namin. :D

Hope this helps.