There are some cheap CNC routers. They often require a bit of setup (i.e. sold as kits) or have questionable quality (3020). I'm not sure you'll find a high quality solution under $500 though.

Shapeoko 3[1] is $1000 USD

X-Carve[2] kits are $800 (upgrade to the Shapeoko2)

3020 Clones[3] are around $500-800 (all over ebay)

[1]http://www.shapeoko.com

[2]https://www.inventables.com/technologies/x-carve

[3]http://www.aliexpress.com/wholesale?SearchText=3020+cnc+rout...

And the ones that cost $6,000 aren't that good (although definitely good enough for hobbyists). Most of the milling machines have a really limiting range at that price point. You can only really mill out flat objects.

Take a look at the X-Carve [0] for a cheaper alternative.

There's also the Othermill [1].

[0]: https://www.inventables.com/technologies/x-carve [1]: https://othermachine.co/othermill/features/

I bought a ShopBot Desktop with a spindle, and it cost about $8,000. I decided that I wanted to focus on my phone project, rather than on trying to get a cheaper/homemade machine to work properly. (It's the same reason I bought an Apple laptop.)

If your budget is limited but you still want to get a sense of designing/making physical objects, buy a lot of Renshape foam, x-acto knife, and laser print designs to trace/cut.

Once you do that for a few hundred hours on your designs, shoot me an email and I'll be happy to mill them out for you = )

On the speaker page for the conference this took place at, it says that Kevin is a hobbyist industrial designer. Likely a good purchase for him!

There exist plenty of "Desktop" CNC Routers -- these are generally cheaper but have a smaller workable space than what comes to mind when you think of a classic CNC Router.