Music Banter - Need Recording Microphone Recommendations (extreme metal guitar)

OK, so... I need two microphones to record my guitar at home. I have one Optimus 30-3018 currently (unidirectional dynamic), which ranges between $9-$20 on eBay. It works decent enough, even recording my guitar, so I will continue to use it for vocals. I just need two of the same microphone to record my amp in stereo (4x12 stereo cabinet). A dynamic microphone preferred, but I don't want to spend a bunch of money for home recording demos if we end up recording in a studio.

I looked at the standard Shure SM57 that nearly everyone uses, which is nice. Something like that, but that won't cost $100 per microphone (not including microphone cables). Any suggestions?

And the reason I want to record my guitar in stereo is because it sounds better and the way I do mixing. It may not be the "right way", but it's the way that works best for me. My rig (a Blackstar HT Stage 100 through a Bugera 412H 4x12" cabinet) sounds so much better in stereo (especially with the reverb and resonance settings I use) and I don't really have a lot of recording equipment or the ability to put the rig in a chamber/room or something. I am just going to close-mic the top right and bottom left speakers at the centre of the cone and do two tracks simultaneously. I have an M-Audio M-Track USB input thing that I use with Reaper.

Short version/more info
• Wanted: two dynamic, preferably unidirectional microphones, preferably also with a flat response.
• Price Range: don't want to spend more than about $100 total for both microphones and two microphone cables
• For: at home recording demos of extreme metal (black, death mostly)

I tried looking for some used microphones in good condition, but couldn't find any that I know would be good. I also want two of the same microphone.

Please, don't worry about why I record the way I do or mix the way I do, I don't care what your opinions are on that. Just give me what I am asking for or don't bother responding. I am asking something very specific, answer what I asked about and don't worry with why, or don't bother. Thank you. Yes there are reasons, and they're entirely irrelevant unless you're wanting to recommend something other than what I am asking for or to tell me I am doing things wrong, in which case you're not going to change my mind, so don't bother. If I want information on recording, mixing/mastering, then I will ask for it.