This is mostly just in the USA. Down under in AUS/NZ it's quite a different world for the prices of refurbished business PCs. I would still opt for something newer than Ivy Bridge as you'd have to use a newer SMBIOS after Catalina for the 8300 to work and that wouldn't be optimal. I think that iMac 14,2 might still survive the next round of Apple cuts but 13,2 certainly won't.
Here in the US we are lucky to get the lowest prices anywhere.
Here are some HP 600 G3 prices in OZ. The first two have the slower weaker T series i5 CPUs and they are like Mac Minis with no internal GPU options for better graphics. The third one, that you could upgrade would cost about 520 USD so not a really great savings over building from components yourself.
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