What's a SOund Cloud?
Taken to the illogical extreme, if you want "as many cheap mics as possible" why stop with that list? I bet you could get 40 or 50 cheap Chinese knock offs for your $500! None would be worth using, but you'd have plenty of mics.
Seriously, I've heard a couple of mics on the cheap list and, while they're okay for the money, the OP is looking for an improvement on what he has and things like an MXL990 aren't going to do that.