@oh_Cosmos Visions Electronics only has higher-end, and higher-priced, gaming systems. Amazon's and Walmart's options are overpriced for the hardware; it looks like they import the computers from the U.S. and tack on a sizable surchare. That's also true of the relatively few offerings on Staples and Memory Express, at least at the moment. Costco has almost nothing at the moment, although that's a good place to check just in case it happens to stock exactly what you want at a given point in time. The others either don't sell what you want or charge way too much for it.
So that leaves, unfortunately, Best Buy, at least for the moment. This is the cheapest good system I found on either site, open box but you said you didn't mind:
https://www.bestbuy.ca/en-ca/product/open-box-asus-rog-strix-g13-gaming-pc-dark-grey-intel-core-i5-14400f-1tb-ssd-16gb-ram-geforce-rtx4060-win11/17930204
It's significantly more expensive but also significantly more powerful than the one I linked from Canada Computers, so much so that it's overkill for Sims 4 no matter how much extra content you pile onto the game itself. I would say it's better for Cities Skylines as its processor is a little faster for gaming, but not that that the upgrade is worth $150. On the other hand, once you pile on the taxes and shipping, the price might be closer, especially if Best Buy's shipping is free. This system also has very new hardware, which is always a bonus when buying open box.
It does look like this sale is going to end today (June 6), so if you're sold on it, don't wait. If you're not though, perhaps other good options will show up in the next couple weeks. While I don't see anything else worth suggesting from Best Buy—the next system with equivalent hardware is $100 more and also open box, and not of the same build quality—stock turns over fairly quickly on the site.
Another option, in general at least, is Newegg Canada. I don't know how you feel about the site, but buying new from Newegg directly should be fine; it's the third-party sellers and the used items that cause problems. If you'd like to compare prices, here's a new system from Newegg's in-house system integrator, meaning they take standard components and assemble them into pre-built PCs. This one is just a touch below the system above:
https://www.newegg.ca/p/N82E16883361009?Item=N82E16883361009
If you're not happy with the Best Buy option and would like to keep looking, that's understandable. Let me know, and I can check the site in a week or so to see whether there are any better options. It's very fast for me because I don't have to look up the hardware, so don't feel like you'd be imposing or inconveniencing me.