I've been ordering parts online from a Ford dealer in Washington state that gives a discount of 25% or more. Most parts can be ordered from their internet site (
"Ford Parts" At Bowen Scarff - Formally 1stfordparts.com .). If they don't show it, you can send them an email and they will get you a quote. It takes a few days for shipping, but if you can plan ahead, it will save you some cash.
I've also done OK buying used part on eBay.