A 9th gen i5 and a GT1030? Who told you that crap?! The reverse of that would almost be putting this RTX 3090 into a Celeron or Athlon machine...
Persona 5 at 4K, doesn't seem to need much in terms of CPU versus GPU, i'll check the sysreqs.. I think my old GPU would have done quite well (1080 Ti) but if you have a low end budget and want 4K 60fps you might do better finding someone selling Xbox One X consoles.. That may seem sarcastic but i've been offered several with many games for around £180-200 which, for the power, isn't that bad!
Wanna buy a Jailbroken PS4 slim? Haha..i've only used it for Linux and RetroArch so...not that much use to me.
Edit: Just looked up the minimum/recommended.. It doesn't want much! Though a GT1030, that idea is awful just due to shortages.. Same with the old RX series from AMD, bit long in the tooth as is the nVidia GTX 970.. However that can almost run Persona 5 happily maxed out paired with an i7 8086K so... Hmm..
In terms of GPU, you need something at least in the performance range of a GTX 1060 6GB and even then RAM bandwidth for smooth 4K would be an issue..
A 2070 Super has the RAM bandwidth to definitely push 4K, however with things as they are i'm not sure you'll get a good deal. Before lockdown, though i usually avoid AMD, i built a half decent PC for someone with a mix of second hand and new parts. The prices i paid over a year ago vs now were probably a rip-off, but it comprised a Ryzen 5 1600X, 16GB 3200MHz RAM, a Gigabyte B450M mobo, 256GB SSD + 500GB HDD, 550Watt PSU (not ideal!) and an Asus Strix GTX 970 (i normally also avoid ASUS lol) and the total cost was well below £400, it could handle Halo MCC and Forza Horizon 4 well at 2K so it's a tough one..
Plus, all cards that only have 4GB video RAM will have issues trying to do 4K at high detail..this is why i'm not recommending anything very old gen, not even a GTX 980.. AMD spotted a trick and fitted more RAM just to give their products a little more life, but really 4GB and below is a problem for people mining currency..hah!
Really, any half modern PC would likely do the job for you, the problem is that 4K does need RAM bandwidth even if the GPU isn't that great (hence the 2070 Super example..my old 1080Ti was pretty much faster in every way, but that card has about 484GB/s RAM bandwidth so less demanding benchmarks and games it will easily push the required frame rate you need my friend, so long as you don't use the RTX part! Haha.. I tend not to recommend anything by AMD as a matter of course, but even an RX 5600 area card would likely do. I do have a bunch of hardware sat around so if you'd like me to test, let me know?
I could actually run it on my old 970 for a laugh at 4K, though i have a cheap GTX 1650 low profile card.. Just because of RAM bandwidth (which is what they tend to be mean with on low end cards) in Legion TD 2 i get around 30-40fps at 4K...but that's in a machine with an i7-4770K running stock! Drop it to 1080p 'high' graphics settings and it ran at 60fps no problem with Legion TD2, Halo MCC and Forza Horizon 4!
Anyway, for those who want tl;dr a second hand GTX 1080 or similar is a good bet, as for CPU if you could get an i7 7700K and board, RAM for not much money, it would at least do what you wanted. Just try and get something fairly new with 4 cores/8 threads, even a 10th gen i3 (get the K version if possible) or a Ryzen 3300X would do ya! Main thing: don't get ripped off!
Aavid technology fan, hardware/software and electronics engineer, music lover..
PC: Intel i9-9900K, 64GB Corsair 3200, RTX 3090, EVGA Nu Audio Pro 7.1, Designare Z390 motherboard w/full ReBAR support enabled, 500GB Samsung Evo 970, 1TB ADATA SX8200, 2TB Sabrent Rocket Q4, 2x2TB Crucial MX500 SATA RAID 0, Corsair RM1000x PSU, Crystal X570 SE smoked glass case, unicorn rainbow vomit RGB and custom liquid loop (rigid tubing - ugh!) and many other PCs, consoles, etc. Everything from SEGA, Nintendo, Sony and MS (and Atari STs, Amiga/Commodore, Sinclair, Amstrad etc) to 486/Pentium and above PCs!