Well, a lot of the general advice is still valid. I used to build computers, so I’m not a complete noob at it. It has been a few years, and I haven’t personally put together a rig specifically for mining. But, putting a computer together really isn’t too bad.
First off, I’d say to identify if you just want it solely for mining or if you think you might want to use it for anything else (like, occasional gaming). If it’s just mining, you can skimp on a lot of things, like hard drive space, RAM, and peripherals. Which means that the advice on the video is still fairly valid… heck, the parts might be even cheaper now that more time has passed.
If you’re planning to solely GPU mine, then the main thing is to make sure you get a mother board that supports that many cards - unless your comfortable adding risers. So, 2 PCI slots for a 2 GPU build or 3 for a 3 GPU builds… ideally, if you want to try to expand off of risers in the future also slots for those. Like the MSI z270-a pro shown in the video only has two PCI slots, so if you aren’t comfortable adding risers and want to do a 3 GPU build, that wouldn’t be the best choice.
As far as GPU’s go, if you have a ballpark for your electric rate check out the NiceHash estimates. Like, right now it’s saying a Nvidia 1070 at $.10 electric rate would make about $0.16 a day. Taking a look at E-bay, there’s auctions from $175 to $1000, the latter of which is, of course, silly. So, if your going to be making about $3 a month, how many months are you comfortable waiting for the card to pay itself off? If it’s 2 years, and you expect the profitability to remain steady (which it rarely does) then you wouldn’t want to spend more than $72 on it, which you’re unlikely to find one for.
As Vosk has noted in some of his more recent videos, mining isn’t super profitable at consumer electric rates. But, if you want to do it more out of interest (or, on speculation that prices will go up sharply), then just troll E-Bay and Amazon for a decent deal from what appears to be a reputable vendor. I would suggest looking at the GPUs listed on the NiceHash calculator and checking out prices for those as a start. (Edited to fix typos and grammatical errors )