Okay awesome I will be digging into that forum!!!

I did see your blog article, but I don't have that giant table drill that you have, do you think a regular drill would work? Did the project end up being around $100 total? Even though I'd have no problem spending that much on a light, since I've never made LEDs before, I would probably want to practice on some very cheap projects so I have some room to fail and try again. I'll be looking through that forum a lot so I can find some good newbie projects.

Drilling and tapping is the trickiest part. I did break the drill bits and taps before. Other than that, there is a little chance of failing (for people with common sense), I think. You can probably drill with the hand held drill. Maybe you can first drill a piece of small wood block, and use it as a guide to keep the drill bit perpendicular. The drill bit is skinny, so it is easy to break if you wobble. If you don't want to buy a tap, you can also use something called self-tapping screw.

Some people don't drill holes (I personally wouldn't do this). They attach the LED with the thermal grease (pretty sticky), and use Kapton tape as an insurance.

To make 1x CXB3070, I think it costs $80 or so (including shipping) if you need to get all parts. But if you make more at a time, it becomes cheaper per unit. There is a cheaper place to get the LED (and LED holder) direct from China (KingBrite). CXB3070 is $32.50 and older CXA3070 is $22.50, shipping is $10.

It's good to absorb information from the riu forum (it is probably a bit tough to understand at first, though). Most people there use Cree CXB3590, CX(A/B)3070, or Bridgelux Vero 29. You could practice with Chinese 100W COB LEDs (around $5), but you still need the other components. It is difficult to screw up the connection of LED part, though (so I don't see the point of wasting money on these inefficient Chinese COB).

This project with XF-3535L is very easy. No drill, and you only need to cut the aluminum U-channel with a hack saw. For a given amount of light, it is more expensive, but it has high efficiency.

I bought from a reputable US company, BRIDGELUX Décor 3000K CRI 97, Made in China.
It depends where you buy but is much folklore that produced in China is junk.