I just ordered this Metro 360 & Hotshot 2W Combo from ebay (CygoLite Bicycle Metro 360 Hotshot 2 Watt USB Rechargeable Combo Set Rear Front | eBay). Not quite under $50, but it comes with the Hotshot rear flasher, and was under $70 with free shipping. The rack mount wasn't included, so if the one I have now isn't compatible I'll buy it from either cygolight spare parts, the ebay vendor (says it'll be available by the end of the week), or rig something up like I talk about in this other post: http://www.bikeforums.net/electronic...rear-rack.html.

I wanted something I didn't need to worry about breaking, buying extra lenses for, and that didn't have an external battery pack. mtbr and bike light database have some beam-shot comparisons that make deciding easier. I'll let you know how it works out.