I have had and used a Canonet QL17 and an Olympus XA (Canonet since the early 90s, XA since maybe the late 90s). They are both 35mm RFs but otherwise pretty different. Obviously the Canonet is the refinement (and more or less end point) of the standard compact RF with manual controls, while the XA is aperture priority and fits in one's pocket. The Canonet and similar RFs were originally marketed as a sort of junior or simpler camera for a person who didn't want or need the complexity and expense of an SLR. I remember my dad buying a Canonet as a present for my cousin, around the time I got my first SLR; this is how I remembered it in the early 90s, before one could quickly look everything up on the internet. In contrast, the XA was since its introduction always sort of a premium camera with an aura of design-object, full page ads in photo magazines, etc.
When I got the Canonet used, it was not terribly fashionable or expensive (however, the black ones have always been very uncommon). It took significantly longer for me to get a moderate-price XA (under $100 or so) - this was during the film era, so neither had yet suffered digital-era devaluation. I enjoy using both of them, but they are different and I don't think a direct comparison of their prices is particularly illuminating. I also don't think KEH's "buy" prices tell us much that is useful. They reflect some combination of what KEH thinks the camera will sell for (user demand), the supply, the ease/difficulty of finding an example in relatively unmarked condition, etc. There are so many working film cameras out there, that one may buy a pretty decent 35mm SLR or compact RF for less than the cost of developing two rolls of prints. So we should go out and make pictures.