I didn't think I'd have a lot of mic's when I first started here 2 1/2 years ago, or so.
Then I got an ecm8000 and a preamp w/ phantom, and then I had to upgrade from that mic and it just grew from there. If you're gonna be recording and trying to perfect it, you'll be getting a bunch of mics. It just happens, and with these cheap mic prices, it's easy to aquire a nice bunch of them. Then you get a good idea of how they compare, just by using them. And I have 3 cheap pre amps too.
I don't really see any way around having a few different mics, some pre's and learning on your own what the possabilities are with them.
Then I made a bunch of tracks w/ different combos of stuff and now I sit here every once in a while and listen to the CDs I've made of the samples and then every once in a while I say, 'hey, what the hell was that sound? It's great.' And then I replay the track and listen to what I was saying that I was using for that sample track.
I include info on the mic, the pre, the pre settings, the placement, the instrument.
But If you can get 2 mics for the price of 1 and they aren't too bad, I'd do it. If you think you really need a matched pair, then you have fewer choices, but you'll also need a matched pair, or a 2 (or more) channel preamp.
Personally, I think a matched pair of mics is something rather advanced for me b/c I can't yet hear the problems w/ an unmatched pair. And untill my ears learn enough to know what I'm listening to, then I'll go for that, but it still takes me a long time to hear the differences in my new gear, and sometimes I have absolutely no clue and I can't hear the diff and I figure I'm either fatigued, don't really care, not able to focus at the moment, or, there's just not enough of a difference for me to have an opinion.
I have some tracks that sound astoundingly similar and are still of high qualtiy and I still don't care which one I'll use b/c they are all good enough, and they are all different signal chains. Then I realize that It will matter more when it gets into context, in a song, a track, a production, a combination with other instruments and then the differences make more sense than abstractly soloing them.
Maybe you've gone thru all of this already, but if you're looking for a mic or mic set and it's the beginning of your mic collecting, then I'd try to get a few diff types of mics before spending 3x more for a matched pair. Or, get the pair and go from there, it's just one more POV.