Here is a message that I received from another small ruminant extension person out in Minnesota.
The USDA-AMS has started to release a Grass-Fed Lamb & Goat price report every month, the first one this past May 13. It can be found at:
http://search.ams.usda.gov/mnreports/nw_ls112.txt
The following link is a blog about its release:
The North Carolina Department of Agriculture will also issue a pastured lamb report. Here is the url for the first one: http://www.ams.usda.gov/mnreports/ra_lo102.txt