Hospital Wool Blanket FullSize 100% Wool Used Good Cond $9.97 buy 2-4, sew them together for size/thickness..
US Style Disaster Blankets Package of Three 30% Wool 91x65" New $14.97 maybe not the % you want, but cheap at ~5.00ea..
You've probably seen all of those at Cheaper Than Dirt, there are also the swiss blanket for $20, and the Italian, and German blankets for $10
There is also the 70% wool/30% acrylic New Zealand blanket for $25, the British Military Wool Blanket for $15, Norwegian Military Wool Blanket for $18, Israeli Wool Blanket 80% wool/20% other for $13, Russian Wool Blanket for $20 (says never issued), New Czech Military Wool-blend Blanket 80% wool/20% other $20, all from Sportsmans Guide. There was a swiss blanket at about the same price as Cheaper then Dirt, and what looked like a 12 buy of the 30% wool/70% other blankets for $60, available from Sportsmans Guide too.
What you get all depends on what you want to use it for.. I've never used eather of the websites myself, but I've been keeping an eye out on the blankets for a while now.. I don't have the room right now but when I do I may get a few of them when I can.