I'm sorry that I didn't mention this earlier. One useful site is https://ca.pcpartpicker.com/ Mind you, I've only used it a few times. This is supposed to find the best online price for the parts you are looking for. It does not consider physical stores, but many of them have an online presence. Interesting factoid: it no longer considers NCIX and related sites due to NCIX's apparent death spiral. One interesting feature is that you can leave your parts collection on pcpartpicker and point others at that list. With convenient links, it is kind of handy for discussions. My son and I partially collaborated on a system for him using this facility (well, the US site because he is in the US). Now, more than a year later, I can still reference that list when he asks me a quetion about some part. (Linux support for his AMD video card has been a problem.)