Your Windows, Your Lamps ($0)
You'd be amazed how far you can get by simply re-orienting yourself relative to the nearest window, or running over to the next room with the great window the next time you have to hop on video.
When you're starting out, the same rules that apply to your primary key light, apply to a window. You wouldn't put a light behind yourself, don't do the same with a window. The window should be in front of you, preferably not directly on-center.
That same can be said of that old desk lamp you've got. In my current office setup, I have a large window letting in loads of blue light. On the other side of my desk, I have a simple desk lamp with a yellow bulb in it. When I hop on video, I turn that light on and it balances out the cool outdoor light with a warmer yellow color. It isn't perfect, but it also didn't cost me anything.
When you're working with entry-level cameras remember the more light you can fill the scene with, the higher quality your video image will be. Cameras can compensate for low-light, but at great expense to quality. Simply increasing the light level will improve the overall video quality.
Foam Board ($3)
Head down to the local craft store and pick up a 36"x36" foam board. You won't believe me until you try it, but a foam board makes for a great reflector on the cheap. Remember most photographers & videographers rely heavily on reflected light. My main set currently uses a reflector, and a foam board is a nearly-free way to get better light control. My favorite YouTuber DSLR Video Shooter uses foam boards in his videos to nail the fill light.
VILTROX L116T Key Light ($45)
Don't fuss with the throwaway multi-light packages in this price range, as they aren't high enough output. You need a single, powerful light to use as your key light. This one's good enough to serve as a background or fill light down the road when you upgrade your setup further.
This one's dimmable, can run on a battery, and has a color temperature adjustment from 3300k-5600k. The built-in diffuser is going to give you a smoother light, and reduce reflections. Keep in mind you need a tripod for this one.
Purchase lights below this price at your own peril! In my $100 video setup, we burn $45 of that budget on this light because that's what it takes today to buy a light with enough output to make an impact on your scene.
Keep in mind you'll need a desktop tripod for this one.
Neewer 2-Pack 700W 24x24in Softbox ($90)
If you recall from the lighting video, the size of your light source rules all. The larger the light, the more smooth & professional your video will look.
This pack comes with two good-sized, 24x24 inch softboxes to provide a smooth, diffused light source. By comparison, my current video setup is a 48" circular softbox - A lighting surface area of 1,800 square inches for around $300. These two Neewer lights combine to offer nearly 1,200 square inches of lighting surface area. Struggle with reflections on your glasses? Never again with this setup.
To take these lights to the next level, mount one on a monitor post on your desk for the flexibility to swing that light in close while you're filming, and push it out of the way when you aren't filming.
Neewer 2-Pack 20x28in Dimmable Softbox with Color Filter ($160)
You'll notice a trend here: we're looking at large lights. This is the next step up from Neewer: they're dimmable, the color temperature is adjustable, and they even come with filters you can put over the light to change the color of the light itself.
Unlike the parabolic softbox design I use, this rectangular design gives you a big surface area to diffuse the light while not being too deep. These ones come with a remote (remember, you're lazy) and a handy carrying bag for taking your show on the road.
Remember the key with lights like this is to design a setup you can coexist with. They're big softboxes, so ensure you've got a way to push them out of the way when you aren't using them. You can buy more compact LED panel lights in this price range, but they'll have around 1/8th of the surface area, which will make a massive impact on the quality of the light.
Aputure Amaran 100d ($200)
Welcome to the big leagues! Your first pro light - you'll never go back.
A light from the leader in professional lighting, the main difference you get going to a pro light is the ability to accessorize, and OUTPUT. These lights will put every other light you've seen to shame.
The 100d is dimmable, and comes with a 'Bowens mount', which is a style of mount that you can use with all sorts of accessories. It's worth noting that you likely won't use this light straight out of the box without some sort of accessory attachment. Check out 'Bowens Mount Softbox' on Amazon to get your wheels turning, or the modifiers on Aputure's website. For an office environment, I'm a fan of the space light.
Aputure Amaran 100x ($250)
The light I'm currently using - the main difference to the 100d is you have additional control over the light temperature. Shooting next to a large window? You'll likely want your light source to be warmer.
For another $50 you have a light that will do the job in any situation, just remember you'll still need to pair it with a modifier.
Much like camera hardware, your next purchases are probably various accessories for your 100d or 100x. You can achieve a number of different effects with modifiers, and I've now bought three 100x's before even thinking about upgrading to a more powerful light.