Ask HN: Why are some domains 3 figures and others are 6?

I was looking at sedo and noticed that the domain qi.co was going for “low six figures”, while the domain qi.do was just under $1k. I picked up the latter for my project, but I’m curious why the massive gap. I understand that .co is seen as premium over the DR’s domain but why I’m curious about discrepancy since consumers will likely not see it much different.