[TheOtherHobbes]

>Could you get to near-perfection by simply increasing the number of microphones used?

No. Ears are (kind of) point sinks. Which is why dummy head stereo works so well on headphones - it's literally recording the sound that would usually go into your ears, as opposed to normal stereo, which records something that's usefully but rather distantly related to what goes into your ears.

Two microphones are enough for that.

A side point is that everyone has a slightly different HRTF, so it would be interesting to hear what you'd get with a neutral point sink recording convolved with your HRTF.

>Also, could using cheap microphones be compensated by using more of them?

No again. Cheap microphones add non-linear distortions and have a limited and inaccurate frequency response. If you use more cheap microphones you just get more of the same.