In the first video, The creator states that it is NOT worth the $200, He shows the system underperforming with current games, and explains that he had to buy a used Graphics card and a used Power supply- on top of the original outlay of $200, making it actually cost around $300, and even then only barely capable of playing the games he benchmarked.
In the second video the creator states that it would be nearly impossible to replicate what he was able to do because he got very lucky with deals on working used parts. He also recommended buying a stolen Windows 10 key from eBay. Either that or he's stupid enough to think that a $5 Windows 10 Pro key is totally above-board.
In any case, In general I'd say what you save in money you end up paying for with your time. Time carefully hunting down used systems or hardware and finding great deals. Time spent diagnosing faulty used components... Time spent, like the second guy did, using a jigsaw to mangle the case to get a graphics card to fit. If you wait long enough or are patient enough you can usually get a good deal on things that would under normal circumstances be more expensive. As long as you are willing to take the risk on possibly broken used components or components that could have issues.
