I am looking to buy four or six, either the WWII spec blankets that weighed about five pounds each or the Cold War-era spec blankets that weighed about four pounds each. Any suggestions on where to find them used and cheap? eBay and Amazon are pricey, and I don't have time this month to go on a tour of Army-Navy stores. (My girlfriend has sleep challenges and some recent research suggests that "heavy" bedding can be beneficial in addressing them. There are specialty blankets that weigh 10-12 pounds that retail for -- I am not kidding -- hundreds of dollars. I figure two or three heavy old army blankets in a duvet cover are a more cost-effective way to test the potential benefit.) Thanks!