1) I don't know of a "good" mic in the $70 range. But I digress.
B) The recording process is a process of stacking nickels to make dollars.
The core sounds are only as good as the song ---
The mic is only ever as good as the core sounds ---
The preamp is only ever as good as the mic ---
The converter is only ever as good as the preamp ---
The interface should be completely transparent to anything but a data stream ---
Then the mix is only as good as the core sounds that make it up ---
The production master is only ever as good as the mixes the mastering engineer is presented with ---
Going 'backwards' to some extent are the two 'rules' that govern basically every other 'rule of thumb' -
1) No matter your gear, no matter years of critical listening experience, no matter the core sounds, you will only ever hear as accurately and consistently as your monitoring chain allows you to hear - Period, no exceptions, end of story.
2) No matter how accurate and consistent your monitoring chain may be, it will only ever be as accurate and consistent as the room that chain is in allows it to be - Period, no exceptions, end of story.
"A good mic" is ONE - tiny, simple link in a long chain that makes up a quality recording.
THAT ALL OUT OF THE WAY:
Of course you're going to need a decent preamp. You're going to need *A* preamp before a mic will do much of anything. And again, that preamp is only going to be as decent as the following pieces in the chain (in this case, the converters, interface, etc.). If you have a common 'stock' sound card created without regard for sound quality (most aren't - that's pretty normal), don't expect much from it.