Ask HN: What do you use for your helpdesk?

I’m sort of amazed how expensive almost all Helpdesk software is. It’s pretty simple stuff, and I would hazard a guess that most customers use a pretty limited set of features.

I know there are a bazillion competitors out there, but do people think there is space in the market for a decent, simple helpdesk product that tried something different with the pricing model? Maybe based per # of tickets as opposed to # of agents. Something like that? Or just something that charged $5 per agent but gave you all the features at that price point?

Thanks!