A few thrift shops I've visited are in the unfortunate habit of marking prices in permanent black marker in their book fronts. Naturally, this doesn't exactly enhance the value of collectible volumes...
As for the Salvation Army, one of the biggest problems I've had with their stapling practice is that it's a pain to get the little suckers out of nice silk ties without harming the fabric. Usually they staple on the area that becomes the rear of the tie when it's around my neck, so that's not quite as bad, but sometimes they staple right through the front... grrr. (It's painful also to see what those staples do to silk shirt collars).
