Your right terrawarra, it does not take a rocket surgeon to make a tamper.
Not all tampers are created equal though and cost does reflect this.
What most of us are paying for is either looks or correct fitment(custom milled). The rest of the cost is usually name related.
I think of my tampers as a set of wheels. They are a must but other than serving that one purpose, they are mostly cosmetic but a really good one can make a difference in usability.