I've used Rock Auto for years. Like said before, just watch the brands you are picking and where they are shipping from. I got the entire front end for my truck for less than 1/2 of what the local parts stores wanted for the same parts, even after shipping.
Funny shipping story: I needed a rear door handle for my Silverado. Sherman's used to be at the end of my street. They had them for $45. The same part at Rock Auto was $8, $11 with shipping. To big of a difference to not give it a try. The part shows up with a return address from Sherman's. I saved $30+ by not driving a mile and a half!