I have no idea how they sound, but Rode has an active system cardioid -- the NT6. Again, like the km140s in that the system has a mic body and a separated active capsule head. Looks to be $370 each new, or less (bhphotovideo say email for lower price).
The Rode mics don't have a very good reputation in the taping community. I've never listened to any of their products, so I can't offer an opinion, but Rode seems to be the first lower cost mic company coming out with an active system (recent years that is).