I recently recorded a whole bunch of mics one after the other from a C1000 to a AT4033 an AT 873R, MXL 990 and 991,
a Rode NT2 a Neumann U87 to a $50 stageworks mic. There were eight different mics on the CD demo I produced, and I made sure that the volume was all the same level so that there would be no bias.
I first spoke into each mic, then played my nylon string guitar into it.
I played this tape back to the guy who lent me the U87 and he said that he didn't like the U 87 as much as some of the other ones. (Honest guy!)
I also played the recording to a bunch of band members on the way to a gig, and the AT 873R got top marks.
I can honestly say after A/B-ing all these mics that spending $3000 on a Nuemann may be a good finacial investment, as they may keep their value or even rise in value, but as far as sound goes, there's no difference, at least on my voice and guitar. However, there may be a difference when you blow horn into a cheaper mic. They can crap out real easy on some of the small diaphragm mics. The large diaphragm (cheap) mics work a lot better for this.
I recently bought a Nady ribbon mic, (an RCA 44 knock off) and a Nady tcm 105 (a
U 47 fet Knock off). They both sound great, and if you blind A/B a bunch of musicians on the $3000 mics against the $300 mics, they will all come up with different answers. Of course, most engineers who've spent five grand on a mic will fiercely defend the "deep", "rich", "warm", "transparent" sound of the real thing right!
I'm not buyin' it!
The other electronics companies have streamlined the manufacturing techniques in countries where the cost of labour can be as little as $300 a year. That's why these mics are soooo cheap. You're getting the same product made by guys who will build it for a lot less money.
Just like buying a Mexican Fender instead of a USA Fender. Same product, less money.
The best thing to do is BLIND A/B a bunch of expensive mics against a bunch of cheaper mics for yourself.
I guarantee everyone will have a different opinion.