That is actually a really really bad decision. If you wanted something with more testing around it, the Seasonic M12II EVO would have been the better choice. I checked eBay AU and the only model (the 620W) is still cheaper than the Focus 450W. It's also fully modular unlike the Focus 450W. I'm using the CX430 from after they did the OEM change from SeaSonic to some C tier OEM and it's been 5 years and it's still going strong.
I don't know how much storage he uses but I don't feel like a lot of people can live off of a 256GB SSD. You were probably better off getting a 1TB HDD like the WD Blue WD10EZEX, a 1TB Seagate Barracuda, or a 1TB Toshiba P300. That gives you more wiggle room for the PSU and GPU.
I REALLY wanted to squeeze the 6GB card in there, but that's just the way she goes. Sometimes she goes, sometimes she doesn't. (I don't know what that is from but I've been saying that a lot lately much to the annoyance of my buddies)
Used parts aren't allowed unfortunately, if I had it my way it'd be a 1070 + old workstation rig ahahhaha.
If I went for the 6GB, the motherboard, PSU and SSD would have to be downgraded for an 8% improvement in minimum framerates. Yes, there are some games where the 0.1% lows tank a lot because of the VRAM but you can just turn textures down a little and it's fine (especially at 1080p, textures don't do much for you in terms of visual fidelity). In 5 years time what's the difference between a 30FPS plus stutter and 33 FPS without stutter from having more VRAM, we're going to be playing on medium anyway to keep the framerate up, hell by that time the $120 saved can probably buy a 1060 6GB. =P
The bottom of the barrel A320M boards don't have heatsinks on the VRMs so their lifespan is questionable, going for B350 also opens up overclocking in the future as old used Ryzen chips will be cheap in 3-5 years, it's not like we have to get K series unlocked parts with inflated second hand prices (they are still pricey here). I think the $20 here is well spent.
The SSD I chose was the Intel 535 360GB, 5 year warranty for $120. $20 more for 50% increase in capacity here is also money well spent. They will put one old HDD in as storage so the space isn't too much of an issue, but 256GB gets really annoying with how big games are becoming now. Not having an SSD is out of the question for a 1K computer in 2018, the experience of using a HDD with Windows 10 is frustrating as hell with all the housekeeping and updates going on in the background.
The Seasonic 450W was ~$115, that's about as cheap as you can find a tier 1 or even tier 2 power supply in Australia, I know warranty isn't indicative of build quality but instead of rolling the dice we will know the PSU will provide 7+ years of service. The upgrade from 5 to 7 years warranty is another potential upgrade cycle and since it's a top tier PSU I think the chances of it taking other parts with it is as low as can be. It'll also be quiet! too, cheap PSUs tend to have their fans run non-stop. (heh)
This person is upgrading from the Radeon 5000 era so reliability is just as important as futureproofing. That's nearly ten years ago and I'm pretty sure I built that PC and it's gone through two family members, ready for the third to some kid playing minecraft with a texture pack or whatever kids play now. Chances are, the PC will never be cleaned, will be left on for eternity and let's be honest, I'm almost positive it'll just go through another 5000 hours of Dota 2 or LoL anyway.
If the difference was just $50-60 as it should be, we wouldn't be having this conversation, but right here and now it's $120 and I think the "intangible" sacrifices are too great to ensure a decent experience in 3-5 years time.
A $200 card three generations from now will obliterate the 1060 6GB, this is the wrong time to over-invest in the GPU, ESPECIALLY if the short term gain is only 8% in addition to there being crypto madness with wacky pricing AND the next generation is around the corner as well. The 360GB SSD is a great deal, SSD prices aren't going down that much, the Seasonic will keep on trucking for a decade I'm sure.
In the grand scheme of things turning textures down is a minor annoyance compared to a mobo failure, PSU failure, or worse, living with a HDD for the next 3+ years and then calling me back to help move from an HDD to SSD. So we'll have to turn textures down a click, big deal, apart from some poorly optimised turds it's hard to imagine AAA devs alienating 70% of systems with 3GB VRAM or less.