What do you consider cheap?
A few Amazon lavalier mics run into some smartphones is the cheapest way you can go. I've seen surprisingly good results with this, but you have to be pretty careful because there's a large margin for error, and you have to worry about the plugs popping out if there's some larger movements being made.
A pretty standard setup I've seen is Rode NTG2 run into Zoom H4N. I like that option because if your mic craps out you can use the onboard H4N mics, and mount it on
In Canada you can rent these for I think around $75/mo through Long-McQuade; I'm sure they can be rented equally cheaply in the states.
I've only ever seen people use treadmills, or film outside with someone carrying a greenscreen behind them as they walk on a key-green fabric.
I usually see the low profile ones from effects equipment companies being used.
If you want to go really shoestring you could consider shooting waist-up, and using a climbing harness suspended from a frame made of 2x4s, with something like a weight hung from the harness to keep them upright without stabilizing with their arms
The only thing I ever see people say is to get out there and work. Do everything you can to gain experience and meet people as you gain it. Make movies on your own and show them to everyone who will watch. Ask if you can shadow people. It's all about who you know and what you've done. Also people say you need to show experience with cameras like the Red EPIC.
YouTube is alright, but it's kind-of saturated, and people on it are more interested than content than the quality it was produced with (look at all the top YouTubers, they started with some wretched equipment).
Have you run the Windows colour calibration tool?
Also, maybe try viewing in on a phone to see how it looks. It'll be close to what people will view the final result on, and they're pre-calibrated.
Just get a phone with a good camera and download a program that lets you mess with settings like ISO. https://www.youtube.com/watch?v=wZI6ha7SzC8 this was done on the iPhone 6.
For Apple there are some accessories that let you add some not-too-great lenses for DOF and UV etc.,
For Android there are clip-on lenses and ones that are magnetized.
Then there's the BeastGrip which works on both lets you add regular camera lenses to your phone (the quality is slightly lowered, but it takes skills to make it look good on either setup [camera vs phone w/ BeastGrip])
If you don't want to use a phone, wait till Summer cause Black Magic often does a deal on their pocket camera. Hopefully next summer they do it for the Micro.
Don't forget that you can rent cameras if you want to try something. I used to make the mistake of buying tons of music gear for stuff I'd only use once in a while. Like with the Sony cameras, I'll rarely be in a situation without custom lighting where I have to use the crazy ISO features.
If you insist on getting a regular camera, I've heard the EOS M3 is a pretty good value camera
I'm not sure how well it would work, but you could shoot using one of those 3D GoPro rigs with both of the cameras at 4K. In post, the resolution would let you zoom in some (though noise is an issue there). You could also use difference modifiers between shots from each camera to do the depth of field and focus.