I've recently put a Rigida Grizzley Carbide rim on the front of my Raven. If it lasts twice as long as a Mavic I would have broken even. If it lasts three or four times as long, as some people are claiming it will, it'll be a great saving. Apart from the price, I'm very happy with it, the wet weather braking is better than with any other rim braking I've had, including Magura HS. The only downside is it squeals, like nothing else.
If you're looking for cheap, try the Rigida Sputniks. Compared to Mavics they're half the price, a little heavier and don't have the reputation for cracking. Another option is the DRC rims, I have the 700c version and they've been faultless.