need to buy a more effecient purifier

Hello, I currently own a honeywell 50250 air purifier and im very pleased with the results it's a great purifier, But it uses to much electric. So im looking to buy a purifier in the $300-$350 price range, And it must clean the air as good or better than the 50250. I was thinking of getting the the rabbit air biogs are they any good?