Might see if any talk radio hosts would help me get the proper equiptment to do it without getting noticed(example, give me one of those things news anchors wear and I'll pin it on the inside of my jacket.)
Those ar high functioning pieces of audio equipment.
Radio shack used to have some stuff that is priced in your range and would work. Sound acutated tape recorders and the like that fit in your pocket and are made to pick up "faraway" sound sources with less echo.
There is also a DAT (digital audio tape) stereo microphone (mic) that looks like eyeglasses or fits into a hat. These can be gotten for less money today because DAT is getting old. People used to use them for recording concerts and such. They work with battery powered DAT decks.
Talk to your parents about it--it may be illegal!