Go look at the 6mmBR.com site. There is a member called "TexasShooter" selling 500 brand new 6BR Lapua cases for $60.00 for a 100 pieces. Look at the shooters forum under the section "6BR, 6BR Improved & Wildcats" and than look for the topic of "Lapua 6mm BR brass"
Hope this helps. Let me know if you find them.