[crazygringo]

It's just like taking a "shot in the dark" with beers.

Beers have all sorts of different flavors, olive oils too, and honestly, you're really going to have no idea until you try them. Price doesn't mean anything, you just have to see what you personally like, and different olive oils "work" for different kinds of dishes. You want a pepperier one with one thing, and a fruitier one with another.

There's no way to inform yourself except by taste-testing them. When I move to a new city, I'll buy several bottles of olive oil from whatever shop, none too expensive, and will usually discover I really love one or two of them, and reserve them for salads/finishing/etc. The rest, I'll use for frying/etc. where the flavor matters much less, and then buy cheap Bertoli for frying/etc. once those others are gone.

So you do have to be "serious" about oil if you want to. But if you don't want to, then that's fine! Just buy the cheap stuff, obviously.