I plugged your build into PCPartPicker and changed a couple of things. The extra $20 for DDR5 is worth it and so is the extra for the 980 Pro SSD for the boot drive. You might be able to some a few bucks by getting an 850W power supply but that might hinder a future upgrade if you think you might go that direction.
I'd gladly help you build them so you could save $75x2. Or possibly do it yourself? MemEx will mount the CPU and RAM to test it for free and that's the hardest part.
https://ca.pcpartpicker.com/list/N2qXkJ
Hopefully MemEx will price match the lower prices.
There are cheaper ways to get Windows that are a little shady but will still get you a legit OS.