There seems to be value in everything.

Now a collection of touching personal letters, written by a young Bob Dylan to a high school girlfriend,  has reportedly been sold at auction to a renowned Portuguese bookshop for nearly $670,000.

The 81-year old Dylan, a Minnesota native, wrote the letters to Barbara Ann Hewitt between 1957 and 1959 when he was still known as Bob Zimmerman.

They provide an insight into a period of his life of which not much is known.