I have the original full set of Renzetti wing burners, including the stonefly wing case burners. Got a lot of mileage out of them, and I still use them. Maybe find a set on the web.
There is a reason why the imports are cheap. If your going to buy burners expect to pay a bit for quality. If you buy a used set make sure you can examine them. These are some of the most abused tools and I wouldn't trust that they would align properly if they have been used for a while.
Look here:
http://www.renzetti.com/index.php?option=com_content&view=article&id=74&Itemid=188
I use cut wings instead of burnt because I can cut it however I want and to any size with only one tool.
Mike.