@blaqluv Alright, I found a numbe of options that would work well and are within your budget. These are (roughly) in order of weakest to strongest hardware, which unsurprisingly corresponds to price. I also found a few used computers, in case you'd rather get an older model with stronger hardware; those are at the end.
The lowest I'd go is this one, at $650. Its graphics card is strong enough for ultra settings now, although that may not be true in a year or two, depending on how demanding future expansion packs turn out to be. It also has a mechanical hard drive, meaning everything from Windows to apps would load more slowly. Sims 4 would run the same in live mode, but loading times would be longer. Still, the game would run just fine. The nice thing about this one is it has 16 GB memory, although you could upgrade the others if you wanted.
https://www.amazon.com/SkyTech-Blaze-Computer-Desktop-GeForce/dp/B07NV267C8
This HP is $700 and has a much faster graphics card—the 1650 is maybe 30% faster than the 1050 ti and will in all likelihood be able to handle ultra settings for the entire run of Sims 4. It does only have a small 256 GB hard drive, but it's a solid state drive, so it's much faster than an HDD. Plus, you could upgrade to a 512 GB SSD for and extra $40; although it's not necessary for Sims 4 alone, you might want the extra storage for other reasons (like other games). The processor is stronger than the first one as well.
https://store.hp.com/us/en/pdp/hp-pavilion-gaming-desktop-tg01-1160xt-8mp64av-1
This one is $750 and has a significantly faster graphics card than the HP. Its processor is weaker but still more than fine for Sims 4. It also has a 500 GB SSD.
https://www.amazon.com/Skytech-Oracle-Gaming-Desktop-Motherboard/dp/B0824B445L/
If you really don't like the look of that model, this one has the same hardware and is $800:
https://www.amazon.com/SkyTech-Blaze-II-Gaming-Desktop/dp/B07RHBLV7F/
An Nvidia 1660 is overkill for Sims 4, but it might be worth the higher price if you decide to play other games later.
In case you're curious what's out there, this one is $850 and has a much stronger processor than the others, plus a 1660 Super, which is a little faster than the regular 1660.
https://www.bestbuy.com/site/cyberpowerpc-gamer-xtreme-gaming-desktop-intel-core-i5-9600kf-8gb-nvidia-geforce-gtx-1660-super-1tb-hdd-240gb-ssd-black/6400455.p?skuId=6400455
If you really want to save money, these Acers are refurbished by Acer itself and do have a short warranty window. The first has a small solid state drive, while the second has a large mechanical drive; the second has a much stronger processor. Their graphics cards are equivalent in performance.
https://www.target.com/p/acer-aspire-desktop-intel-core-i5-3-ghz-8-gb-ram-256-gb-ssd-windows-10-home-manufacturer-refurbished/-/A-79856757
https://www.target.com/p/acer-nitro-50-desktop-intel-i7-8700-3-20ghz-8gb-ram-1tb-hdd-windows-10-home-manufacturer-refurbished/-/A-79683806
This Lenovo has a certified open-box option for $790, and it comes with an Nvidia 1660 plus a processor that's faster than the Ryzen 5 2600 in the Skytech models but slower than the i5-10400 in the HP.
https://www.bestbuy.com/site/lenovo-legion-gaming-desktop-intel-core-i5-9400f-8gb-memory-nvidia-geforce-gtx-1660-1tb-hdd-256gb-ssd-phantom-black/6401009.p?skuId=6401009
If you have more questions about these, or any other options you see, please feel free to ask.