It's relatively simple to make an inexpensive omnidirectional condenser microphone that sounds pretty good, and many manufacturers in many countries have learned how to do that. Directional capsules of equivalent quality are more complicated to design and manufacture--supercardioids most of all. Thus the quality of the best available omnis at a moderate price point is noticeably higher than the quality of the cardioids at that same price point--and for supercardioids, the "you-get-what-you-pay-for effect" is even greater.
With supercardioids there is an additional disruptive factor: the primary market for highly directional microphones is public address and film/video sound applications, not music recording. As a result the large majority of supercardioid microphones have significantly reduced low-frequency sensitivity by design. Unfortunately this isn't always evident from published frequency response curves or specifications, since the manufacturers of speech-oriented microphones generally measure their products at shorter distances from the test sound source than studio microphones would normally be measured, on the reasoning that the microphones are intended to be used at those shorter distances. But the closer the measurement distance that's used for a directional microphone, the more bass will show up in the graph due to proximity effect, which is not subtracted out. For sound sources beyond 1 or 2 meters distance, the response e.g. at 50 Hz can well be 10 dB less than what the graph or list of specifications will indicate. (10 dB is quite a lot.)
Finally, I have to lay it on the line: There is no type of microphone that will, by its nature, pick up good sound "from the back of a bad room." A supercardioid will eliminate more room sound at any given distance than any other first-order pattern will do. But those few supercardioid condenser microphones that have smooth, wide frequency response and a directional pattern that remains constant across the frequency range--an especially important characteristic when most of the sound is coming in from fairly random angles--are not "lo priced".
If I had to choose the supercardioid microphone with the best performance for the lowest price, I would probably choose the Beyer M 160 ribbon with the understanding that it can never, ever, ever be used outdoors (ribbons are more fragile than condensers), and that as a very low-output dynamic microphone, it will always be significantly more vulnerable to hum and radio frequency interference than a modern condenser microphone. However, unfortunately, the M 160 isn't cheap, and it would take a lot of trust to buy them used, since one moron who blows into the microphone to see if it's "on" can damage it, although that damage will be totally invisible externally. -- A possible alternative, which is smaller, less fragile and less costly, is the Beyer M 201 N(C)--but it's been literally decades since I used that model, and perhaps I'm remembering it with more fondness than it deserves, I dunno.
--best regards