Rock Auto May be known for lower prices (sometimes) but you’ll pay for shipping and their customer service is non-existent. Lots of horrific reviews on this matter, and I’ve had personal experience with this.
Compared to e-trailer, where you can see customer reviews as well as videos of e-trailer personnel demonstrating their products. I had a question and emailed them. They got back to me the next day with an answer. Received a follow up email from a supervisor asking if the answer was satisfactory. When I purchased the product, I got yet another email ensuring everything arrived ok and I was satisfied.
Or, compared with Amazon. Great prices and fantastic customer service.
You might save a buck shopping at a Rock Auto, but to me, customer service is worth an extra buck or two.