Arrowheads vary in value based upon a few factors. Firstly, the composition, what the arrowhead is made from. Secondly, location it was found which will tell us roughly which tribe made the it. Lastly, the shape will also help with figuring out the tribe and the time period the arrowhead was crafted. Your best bet would be to take it to your local university or college and ask a professor of Native American studies.