Yes, I have sold many images for $50.00 or higher - but the most I've received through a microstock site was $35.00 for an extended license.
Surprisingly, my biggest dollar amounts have come from people contacting me through my Flick account and wanting to use one or more of my images. Just last month I sold two photos via Flickr to a calendar company wanting Texas images and they paid $150.00 per image.....