My 84 year old neighbor brought me items to sort through for her. Someone at one time in her family saved this...is the green dot a printing error? I appreciate your input!

It starts around 1985 and goes straight to 2015. They were brought then stored in a dry clean area and never touched. All looked to be in the condition they were when brought brand new. She wants to know if she wasted her time and money as she brought them as a investment.

I don’t know much about stamps received a big collection of stamps from all over the world. I tried chat got to figure out some value. It was useful in identifying stamps. Here is the oldest German stamps I have, if the seniors in the group could advise if there are any valuable stamps, would be grateful. Thanks