Looking at all those desktops, you'll want a Dell, that I can tell you. Dell, in my opinion makes great hardware and with all the Dell's I've owned I never had a hiccup with hardware. Now that's not to say they don't make duds, all manufactures have their duds.
Now from a Dell angle, I see a Dell XPS 8500 with a Core i7-3770 CPU @ 3.40GHz, 8GB RAM, 1000GB HDD. This desktop's CPU ranks in at 6,368 at Passmark. That's 3,288 points higher than the CPU you have now. BUT!
This custom build desktop, Custom All Series with Core i7-4770 CPU @ 3.40GHz, 8GB RAM, 1000GB HDD has 7,024 Passmark points which is 3,944 points higher than the CPU you have now.
Now that's just from the CPU front. I have no idea what kind of hardware are in these desktops pertaining to its motherboard. 8 GB of RAM would be the minimum I'd get. If the picture is correct, it may sport an Asus optical drive which is decent. Now many people don't care for optical media, but I love it for backups of data and the bit integrity is far, far better than a hard drive that is flash-based or magnetic-based where you could get errors. I use a Pioneer Blu-ray burner and burn to 25 and 50 GB disks for my website backups and other stuff. Then those disks are stored in a $35 fireproof safe. The once in a while full hard drive clones are cloned to an external USB hard drive and that hard drive is stored in a sandwich bag and placed in the fireproof safe. Just food for thought here about backups. You can't have too many backups and redundancy.
Now here's a thought. Since you indicate you are low income. If you get EBT or Medicaid you can get Amazon Prime at 50% off for around $6 a month. And some of Amazon's products including full desktops allow you to make payments with no interest or credit check required. Now not all of Amazon's products are like this, but if you go
here, you'll see the search query as 'payment plan items.' I've found not all items listed qualify for payments, but many do. Look for AMD-based desktops and go
here and compare the Passmark score for CPU capability. AMD is the budget friendly CPU all the while giving you great CPU crunching power. Also factor in the type of hardware they offer versus other offerings. You may be interested in a laptop as well. But with laptops I'd go Dell or Asus myself, but you have to read up on reviews all over the Internet. Use
this site to get a feel on the quality of the Amazon reviews. This rating, A through F is
NOT a rating on the product, but of the reviews and whether they can be trusted or not. It
DOES NOT mean it's necessarily a bad product, just that there may be a lot of fake reviews either pro or con. You enter the Amazon URL from the address bar in the search field top left where it says Analyze.
Now depending on your income, your bills and what not, a long term payment plan may NOT be what you want. I'm just throwing it out there for an option if you so wish. You might very well be better off with that custom built i7-4770.
I need to mention hard drives. In this day in age it's a now brainer to go SSD or m.2. For around $60 you can have a 500 GB Crucial MX500 SSD that will work really well and give you pretty decent data access speed from the drive. You could also go Samsung, but I just prefer Crucial. There are actually three or four manufactures of semiconductor memory chips for SSDs regardless of SSD brand. Off the top of my head they are, Micron (Crucial), Samsung and Hynix. This applies to m.2 as well and maybe even USB thumb drives, I'm not too sure.
You'd want a good quality enterprise grade platter for spill over and very large installs like Steam games. A 2 TB Hitachi enterprise grade platter should cost around $50. I own two. Both are 2 TBs each and were used from eBay and as of now have a little over 22,000 hours of use and still going. I knew these drives would work out so that's why I wasn't reluctant to buy used Hitachi enterprise grade hard drives on eBay. This is what I have.
Newegg link and
Amazon link.
Now there are two things here between Amazon and Newegg. Newegg says a three year warranty while Amazon looks flaky on that. Also, in the Amazon picture it shows SATA II or 3 GB/s (wrong HDD) while the Newegg link is correct in that these drives are in fact SATA III 6 GB/s. The MTBF (Mean Time Before failure) for this drive is reportedly 2 million whooping hours. Did I mention these ARE enterprise hard drives and I only have, oh, 22,000 hours on the drive thus far? LOL These drives were meant for servers for lots of reads and writes. Now they WILL be noisy, but I don't care about that. So long as they last, and you won't hear it hardly at all unless you are reading/writing to the drive or Window is doing clean up routines and other stuff. Also, never over defrag a drive, only if it is really badly fragmented. And of course never defrag a SSD or other flash-based hard drive.
Also, the desktops you gave a link to all use Windows 10. Be prepared for update madness to say the least. "Updates" can and will hose you over so have backups and full hard drive clones and often times "updates" require updates. Unfortunately, Windows 10 is the latest and everyone will eventually will have to use it. I've been testing Windows 10 LTSC in VMware myself, and to make this short I'll just say there's a TON of traffic going in and out of a Windows 10 install out onto the Internet. I don't see this with Windows 7 or even XP. If you could go with something like Linux Mint for what you do, then that may be the better choice. It's just that Linux may have a learning curve. If all you do is small home and office computing then it will suffice.