Way to go!! I too am always out at thrift stores looking for finds like that no matter what town I visit. So far the best deal I have ever found was 11 bags of Molicare Super Plus at 4.99 a bag. I grabbed every bag they had. The shopping cart was over flowing and I had to put some under it too. Since I am bladder incontinent, it didn't bother me for others to see what I had and what I was buying.
when my wife goes with me, if she finds adult diapers she will ask me if they are good ones or not. Normally I don't find good ones and have never found any good ones like you did. The fun of just finding diapers at thrift stores and or flee markets makes the day so much more fun.
Hope you find more and like someone else said, there may be someone close to you that wears and someday you might run into them. Keep enjoying the thrill of the hunt.