there really are a ton of good mics in the 500-800 price range. I'd advise you head over to archive.org and listen to lots of different recordings. It's really the best resource for researching this kind of stuff. Do yourself a favor and take the time to download FLACs and burn CDs and listen on the best system you have available. listening to mp3s on cheapo computer speakers kisn't really the best way to analyze a recording.
it's also useful to just keep a list of recordings that you like. I keep a spreadsheet. If I download a show, which I don't do often anymore, but when I do if I really like the recording I enter some basic information about the recording gear, location, config, etc... Over time it's allowed me to identify gear that I like, because the same gear keeps appearing in the list.
or you could just buy and sell a bunch of gear in the yard sale here and find out what you like that way. It's exspensive, but fun. And I'd be lying If I were to say I hadn't tried that method a bit myself