Hmm. Asking for a detailed comparison of the various different 10-30 dollar mics is a bit like asking for a full discussion of the relative merits of various $2.98-per-six-pack beers.
A few points, just to clarify a few things above.
You said you want a mic that you can input through the
line in of your soundcard, if I remember correctly.
You generally can't plug a microphone directly into a line in. A microphone doesn't put out a line-level signal. (Also a line input is very likely quite high impedance: decent mics -- though perhaps not 10-30 dollar mics -- are all low impedance, and won't sound great going into such an input.
A microphone signal must be amplified by a microphone preamplifier, which amplifies a mic-level signal to a line-level signal. Generally speaking, any input (to a soundcard, a tape recorder or whatever) that's labeled as a microphone input is connected to a microphone preamp. Many soundcards have mic preamps in them.
If you do, as you said, want to connect your mic to the line input of your soundcard, you will pretty much need a mic preamp. A stereo receiver will not generally work, certainly not well.
If, rather, you want to connect your mic to the "mic" input of your soundcard, there may be some interface issues. I don't know much about your standard-issue sound cards, but I think they're intended to work with computer mics which have some different specifications from typical decent recording mics (unbalanced, I think; not sure what impedance; also I think soundcards supply power in some way). Also, I suspect the mic preamp in a standard-issue sound card may not be the greatest piece of equiment in the world. To put it another way: plugging a decent recording mic into a standard-issue sound card's mic input may not accomplish much, and may even be worse than using a standard computer mic.
You might want to consider looking for the best mic that's made for a computer and is in your price range. To do better than that, you may need to raise the price range high enough to accomodate a mic and an outboard preamp (or maybe a little mixer with preamps built into it).
A real "pro" would probably scoff, but if you go the latter route, I think you could get something that might please you in the $100-$300 range (total). For example, an all-Behringer set-up that would raise eyebrows and scowls in some circles (but might make you sort of happy):
an ECM 8000 ($35) + one of those tiny mxers with two preamps in it (about $80, I think?).