While I haven’t looked up the prices for the specific parts, here are a few recommendations:
CPU: I’d pick a Ryzen, probably 2600(X) if it is used for gaming alone. That being said, a 2700(X) is also nice.
RAM: Make sure it’s on the mainboard’s vendor QVL list.
HDD: I think the best price/byte ratio is currently found on 4TB disks.
GPU: Personally, I prefer AMD. A RX 590 offers good performance, while a Vega 56 is more potent and offers more tinkering around potential. Also, have you thought about a GTX 1660?
PSU: Personally again, I like to over-provide, but this isn’t necessary. Do NOT try to save money when picking a PSU. Take something with gold or platinum rating. (I think 600W should suffice, but I’d pick 800W )
So, Nvidia currently offers more performance for the same money? (I’m not up to date on reviews. But for me, there are features like Radeon Chill and undervolting potential I wouldn’t want to miss)
Anyway as a general recommendation: You’ll probably install the OS on your friends PC, so don’t forget that AMD’s 4XX platform offers storeMI.
A collection of suggestions:
CPU 8700(k) or 2600x or 2700X, all three capable gaming CPUs.
Cooler: Anything that fits, Cryorig, Noctua, bequiet, etc. You do not want to have the hair-dryer experience!
Case: Read reviews for the cases you consider. You do not want to buy a rattletrap (like I did despite knowing better).
GPU: This is going to be difficult. For 1080p gaming, 1060 6gb, RX580 8GB or RX590. Higher target refresh rate will require Vega 56 or 1070(ti).
At 1440p I would recommend Vega 56 or 64, GTX 1070ti, RTX 2060 (?).
4k gaming is an entierly different story and out of budget.
Storage is personal preference, SSD is good to have.
WHY, why in 2019 would you buy a CPU without hyperthreading?
I am painfully aware it does not do anything in games, but the moment you do more than just gaming (voice chat, browser, media player & game), it streamlines the experience. Problem is, nobody benches that.
Games profit from HT or SMT too. I think HT/SMT can be seen as 1/4 of a core per core. E.g.: 8C/16T offers the same multicore performance as the same CPU with 12C/12T.
Edit: Since the friend isn’t tech savvy, I’d pick a 2600X or 2700X an not a non-X CPU.