There's nothing wrong with the MA3s. I use them on my fixie and they're great. No problems at all. When I bought my MA3s, I found a store online that sold open pros for about $45 each. Seemed very reasonable to me. Look around, you may be able to find low prices on the Open Pros, and if not, go with the MA3s.

If you want to venture away from Mavic, a lot of people on this forum speak highly of the Velocity rims. They seem nice.