Well, a lot of people spend more on one knife, one pack or tent than a decent used entry level canoe costs ( definately more on a bike or ATV). And if you are patient (the tough part) and cast a wide net, you can luck up on a real deal, either a project canoe or a "barn find" to be bought well below it's value. That's on the low end. On the high end, you can easily spend as much on a really nice new "state of the art" kevlar/graphite canoe as a used car or truck costs. And like vehicles, no one canoe design does everything well. So I guess the first move is to decide what you will primarily use the canoe for.
For example, I have a bad lust for a dedicated solo whitewater canoe and drool over every good used or refurbishable one I find. But I know it will not properly fill the hole in my fleet of canoes between the Old Town Discovery 169 "barge" and the Discovery 119K solo. A "heavy duty truck" and a "economy car". The dedicated ww canoes are specialized "sports cars" that, properly outfitted, will neither carry much weight nor be any fun at all to paddle on pool drop rivers. And I am no longer atheletic enough to take on challenging rivers where that type of canoe is most useful. My personal answer is to find a Royalex canoe with some rocker, some volume in bow and stern, some ability to track and sufficient volume to carry my usual load.
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By the way, just so you know, Cliff Jacobson the canoe guru, who could have any canoe he wants including custom one-off boats, paddles a Bell Yellowstone.

("Kevlite" kevlar composit, not the lighter "Black Gold" carbon fiber job)