Reddit mentions of Movo VXR1000 Mini HD Shotgun Condenser Microphone for DSLR Video Cameras

That looks awesome. If you want to do something to record audio, you can do what I did.

I bought this frame (forgot I already had one, but when I bought it, it was on sale for $18): http://www.amazon.com/gp/product/B009PK9QGU/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

...with this audio cable adapter: http://www.amazon.com/gp/product/B00A3MY7L8/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

...and I use this mic for the audio: http://www.amazon.com/gp/product/B00I4DGRCU/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

To get a setup that allows me to record MUCH better audio quality than you get with the camera in its normal case. The audio quality still isn't great though from what I've tested while filming fishing out on my boat. If you can afford it, I would get a better quality mic, but that one is enough and better than what the camera can do.

Ah, okay.

Sorry, the type of video production I am most familiar with is the kind for short film production, music videos, weddings, things of that nature. So I don't feel 100% comfortable trying to give advice on things of this nature. Just from a quick glance though it looks like the adapter to connect an external microphone to your GoPro is $49.00 just by itself.

That leaves about $51 on your maximum budget, which rules out my preferred style of handheld camera microphone, the shotgun mic. If you already have the adapter and therefore don't need to spend the $49 I'd heavily recommend Rode products, specifically for your needs the Videomic Go.

There is this inexpensive shotgun mic bundle that I found on Amazon, but I don't have the experience with this product like I do with Rode products to speak to it's quality. It does record in mono sound, but you can duplicate the audio track in your editing program to simulate stereo. For a quick and cheap setup you can get the adapter and this shotgun mic and that will still be better than audio straight out of the GoPro.

The reason I prefer shotgun mics to lavalier mics is that you have the ability to capture sounds other than yourself if you so desire to, but also lavalier mics have a habit of being obscured by clothing and being affected heavily by wind. I'd hate for you to record a vlog only to realize your sweatshirt had been over your microphone for the better part of the day and now you have no useable audio.

But if you are set on the idea of a lavalier mic then your best bet for the GoPro would be this kit I found on Amazon. You don't need an adapter because it's meant for the GoPro, and it comes with a windscreen which will reduce your wind interference. And at the price this honestly might be your best entry-level audio option for that camera set up to add some production value to a vlog.