Alright, so apparently this Okeyn 3.5mm "Condenser" microphone DOES work when plugged directly into the Astro MixAmp Pro TR for PS4. The sound is a bit airy (my friends in party chat said it sounds like I'm in an empty room; acoustic sound), but it comes through loud and clear. No need for phantom power or anything.
Amazon link to the Okeyn mic: http://www.amazon.com/gp/product/B0140ZEDB2
At only $15, it's a cheap, workable alternative to the setup Sam21 proposed.
Sam21's setup, at the current Amazon prices, would run around $115.
I'll re-quote that exact setup below in the event anyone reading this workaround is also interested in eventually upgrading to a better sound/build quality microphone for the Astro Mixamp.
for the XLR desktop Mics you need these :
(1) A Microphone like this :
http://www.amazon.com/Audio-Technica-AT2020-Cardioid-Condenser-Microphone/dp/B0006H92QK/ref=sr_1_1?s=musical-instruments&ie=UTF8&qid=1445883290&sr=1-1&keywords=at2020
(2) A phantom power supply like this :
http://www.amazon.com/Behringer-PS400-BEHRINGER-MICROPOWER/dp/B000FG795I/ref=sr_1_5?s=musical-instruments&ie=UTF8&qid=1445883335&sr=1-5&keywords=phantom+power+supply
(3) Two cables :
XLR male to female :
http://www.amazon.com/Sendt-Female-Microphone-cable-24AWG/dp/B00EPMXWNQ/ref=sr_1_3?s=musical-instruments&ie=UTF8&qid=1445883410&sr=1-3-spons&keywords=XLR+cable&psc=1
XLR female to 3.5mm TRS:
http://www.amazon.com/Hosa-XVM-115F-Microphone-Cable-Right-Angle/dp/B000068NZF/ref=sr_1_8?s=musical-instruments&ie=UTF8&qid=1445883510&sr=1-8&keywords=hosa+XLR+female+to+TRS
(4) and of course, a nice ADC like the one in Creative X7.
NOTE (Edit): This suggestion DID NOT WORK. Please disregard it, see my edit for details!
This forum is absolutely amazing. I don't know that I'd ever have been as satisfied with my sound setup on PS4 as I am without all of you. Thank you all.
EDIT: I've posted an update (http://www.head-fi.org/t/534479/mad-lust-envys-headphone-gaming-guide-5-31-2015-beyer-cop-and-shure-1540-added/32865#post_12073235) to my working setup for anyone looking for a similar setup. Just browse a few pages ahead or search through my posts to find the detailed setup guide.