Why the Variation in domain suffix prices?

[Domaineer]

I was wondering to myself about the variation in domain suffix prices. I understand that in the beginning everyone wanted the status of the .com suffix and so it became valuable. I understand that not many people want .info because it can look a little lame at times and so it's less expensive. What I don't understand is why from host to host the prices for the same suffixes vary so much. It is not like you are buying different makes or models of cars that will depreciate or appreciate differently. Maybe it's partly because different hosts give various levels of services. Still, there must be another reason, because this doesn't seem like enough. Anyone have some ideas?