I use a Sony ECM-719 sometimes. Honestly, I've gotten some decent tapes with it, and would recommend it as a starter mic in your budget.
Advantages:
Does not require a battery box, you insert a small watch battery in the mic itself to power it.
Simple, single point stereo... it's basically point and shoot... no need to think about mic patterns.
Cardiod pattern should limit some crowd noise, boominess.
Disadvantages:
Frequency range is sub-optimal... 100Hz to 15kHz (human hearing is optimally 20hHz to 20kHz)
No way to change mic patterns
Not as small/easy to conceal as the other mics you are looking at.
Listen here for an example recorded with the ECM-719. Small club, about 10 feet from the stage:
http://www.archive.org/details/raq2007-09-14.ats.flac16If you wanted to spend thousands of $$$ on equipment you could get sound like this: (same show, same taping location)
http://www.archive.org/details/raq2007-09-14For me, the ecm-719 was a good starting point.