I love RockAuto for their website and hate it for their shipping costs! The website lists cheap (economy) parts, daily driver parts, professional and performance for some parts. Buy good name brands like AC Delco, Motorcraft, Mopar and buy for price. Cheap parts for a car you won’t have long and more expensive for long-term rides.
AND I use RockAuto to FIND the part number to cross check for prices and shipping from Amazon or WalMart. RA’s shipping for things like brake rotors can be really high. A Prime membership from Amazon can soften that pain - a LOT. WalMart’s direct free ship to the store also saves a lot. Amazon’s and WalMart’s own search engines for car parts is awful.
EBay or AliExpress for car parts is a risk and I would not suggest them. The auto parts stores sites are just fine. They all sell junk parts as well as good parts. Let price and reputation be your guide. Most times they don’t have what I need in stock and it must be ordered anyway so why not online?