Being able to collect arrowheads like that would be awesome. In the Netherlands stone arrows havent been used for over 2000 years so you wont find that many of em.
One of the things i kind off collect is clay pipes.
The nice thing about them is you can easily date them by size, shape and makers mark.
The smallest one (top left) is from the 16th century while the largest one (bottom right) is early 20th century.(edited)