The first thing to realize is that the mics mean nothing if you're recording from a bad location...such as out of your jeans pocket. You could invest $5k on mics and have the mics in a poor location and the recording will sound like crap.
Location is ABSOLUTELY the most important factor for getting a good recording and a $100 mic in the right place will probably sound better than a $5K mic in a bad place every time.
Having said that, there are plenty of great mics in your price range. I disagree totally with the previous commenter that bass is hard to come by. It depends on both the equipment you have and the acoustics of the show. But great bass tones can be obtained with gear that's considered to be less than high end.
While Church Audio CA-14 mics are stealthy, they're also fantastic sounding mics that can be obtained in the $150 range, so personally I think they're the best of both worlds which is what you describe your needs to be. When you want to run open, just put them up on a stand in the sweet spot and above people's heads (to minimize chatter) and you'll be very pleased. If you can't use a stand, then they're also small enough to put on a hat or whatever.
...but don't take my word for it. Prove it for yourself by taking a listen. Check it out...this recording was made front and center with some CA-14 omni's which new cost about $140...
http://www.archive.org/details/toubab2009-08-14.ca14o_24bit...and this recording was made in the exact same location with a pair of Neumann U89i which new cost around $6400 a pair.
http://www.archive.org/details/toubab2009-08-14.u89i_24bitIf you think CA-14's aren't a great value after listening to these two recordings, I'll eat my hat!
Hint about recording...get your mics up higher than waist level for improved results. Keeping them near you waist is...well a waste. Sound has to get around peoples bodies, which naturally muffle the sound. Crisp pure sound on a recording results from sound waves that travel directly in a straight line from the speakers to your mics. Also, the farther back you are from the stage, the more reverberant sound waves (bouncing off the walls, for example) will factor into your recording. Some reverb can be pleasing and add to the ambience...lots of reverb usually will be less pleasing and at some point too much reverb will ruin a recording.