Simple (stereo) mic upgrade for T3i

I'm finding myself popping out more and more video clips with my T3i. Now that I have a nifty-fifty in the mail, I'll soon have a good prime lens to play around with. So the next step is…
Audio, of course! The in-camera mic is ok in a pinch, but thankfully Canon put in a stereo input jack. It would be a shame to spend $$$ on shiny lenses and bodies while ignoring audio pickup. I'm a complete newbie at this, but this is what I think would be best for my situation.

• I'm looking to upgrade the camera's built in monaural mic on the cheap: <$30 if possible. This upgrade will not be a replacement for a proper mic setup. Instead, I want a high buck:bang ratio.
  
• It should "attach" to the camera body. I have duct tape, electrical tape, a soldering iron, 3.5" cables, wire strippers, and a reckless disregard for self-inflicted burn wounds to facilitate this.
  
• A Stereo mic setup, if it's worthwhile. I got a stereo input jack just begging to be used!
  
• Directional mics. I'd like to be able to whisper or adjust something without plagiarizing a The Perfect Storm soundtrack.
  
• Small mics. Unless DSLRs with antennae are in this year, that is.
  
• I've learned to just manually focus for video. Phase detection: temporarily ruins the video. Contrast detection: temporarily ruins the video for even longer. Meanwhile, the kit lens micromotor sound pollution gives my video clips that horrible "Portal to Hell" ambience, so no more AF with video. Therefore, attachment to the body shouldn't be a problem.
  

I really dont think there is anything out there for less than $30 that will make the sound pickup any better than the in camera... Guess I could be wrong though as I have never even considered anything in that price range.

The least expensive stereo shotgun mic with decent quality is the Azden SMX-10 which I use and recommend for the price;

http://www.bhphotovide​o.com …10_Stereo_Micro​phone.html