Some good advice so far. The only thing I would add is that you need to consider whether you will be stealthing at all, either non-taper friendly bands or taper-friendly bands at non-friendly venues.
If you think you may need to stealth, I'd look at Audio Technica AT853s or the Sound Professionals SP-CMC-4 version of the same mics. These are a good choice to get started IMO, since they offer quite decent quality and have interchangeable capsules available (cardioids, hypercardiods, omnis) so you can really experiment with different setups for different situations. Plus, even if you buy some really nice open-taping mics down the road, you can hold onto these for stealthing. Whereas if you go with the cheap open-taping mics you may not have much use for them once the upgrade bug bites.