I have purchased chips from the following Nevada Casinos by mail (Not recently as I have stopped collecting many LE's)
Truck Inn Fernley
Harvey's (they have even sent me some obsolete)Tahoe.
Cal-Neva-Ari
Harrah's Laughlin
I have also purchased obsoletes from the cage at face from Caesars, Desert Inn (before it closed) Stardust, & Tropicana...you never know unless you ask. Don Anthony who passed away a few years ago put me on to this...I always think of him w/new finds.
Rich Figarotta R-1593