I do not much like your picks.
If you are going to buy new and not used, you get better value from current gen products.
For example, the 12th gen I3-12100 processor sells for $135:
https://www.newegg.com/intel-core-i3-12100-core-i3-12th-gen/p/N82E16819118370?quicklink=true
It comes with a cooler, and it includes integrated graphics.
Integrated graphics lets you defer on the graphics card until prices stabilize and you better know what you want. Intel is due to launch it's cards soon, and I think that will lower the current prices.
Newegg lists the 3500X at $170.
I3-12100 has 8 threads and a passmark rating of 14540. That is when all 8 threads are fully loaded.
For games, expect to effectively use 4-6 threads.
The single thread rating is 3550. The single thread rating is arguably the more important spec for gaming and desktop quickness.
R5-3500X has 6 threads and a rating of 18303 which is better for batch apps, but the
2530 rating is not as good for games and quickness.
Try running the cpu-Z bench test on your FX-4300.
You should get a score about 250:
https://valid.x86.fr/bench/zksrpi/1
The i3-12100 will be about 657:
http://valid.x86.fr/bench/simj7f/1
3500x is about486.
Here is a review of thee i3-12100:
https://www.tomshardware.com/news/intel-core-i3-12100-12100f-review
A MATX B660 DDR4 motherboard with wifi might be about $150:
A bit less without wifi.
The 3200 speed ram you picked is fine for Intel.
But for amd, which is tightly connected to ram, you would want 2600 speed.
The case is fine.
On the psu, 550w is ok for a 3050 gpu.
But, if, in time you might want to upgrade the graphics card,
Here is a handy chart for sizing a psu:
http://www.realhardtechx.com/index_archivos/Page362.htm
I would buy 650w or even 750w.
The 12100 processor can be good for a much stronger processor.
A psu will only use the power demanded of it, regardless of the max capability.
I do not know much about Phanteks power supplies.
With a 10 year warranty, they are likely made by seasonic.
On storage, I would consider 2tb if it fits your budget.
And for reliability, Puget systems thinks highly of the Samsung ssd devices:
Here at Puget Systems, our goal is not only to provide the fastest workstations possible, but the most reliable as well. As a part of our constant drive to offer only the highest quality components possible, we track and regularly review the failure rates for each part we carry. Today, we want...
www.pugetsystems.com