I know what you're talking about! I've been mixing paraffin wax and oil together and dipping my drivetrain for awhile. Did I mention I started as a hobby mechanic?

There is definitely a difference between a BSO retailer and a LBS, but also between shops for the different types of riding. Some shops specialize in mountain, some road, some commuting. I imagine that some are now even specializing in ebikes, but I haven't seen it with my own eyes in the wild. Go where the knowledge, tools, and parts are for your ride... which is probably the local independent :)