What a very cute milk bottle, Sami!!!
I'm afraid, but I have not seen anything like this before. As for the value of that item, I have to say that your history teacher might have been wrong. There are many older milk bottles from the 19th to the 1960's to be sold for 50- 200 Euro per piece, depending on the age. If the bottle was produced for a special advertising I would not rate it more than 100 Euro, given the information that it was released in the early 1980's. Sorry, but since my friend has bought a couple of old Swedish milk bottles at auctions, I have to correct your teacher.