I've been taking a look at test sieves around me and thinking that they would be fairly simple to reproduce using the appropriate mesh, clamps, and a suitable frame. Is there any reason that this would be at all inferior to the prefabricated sieve? I've gotten price estimates on the mesh (30cmx30cm) alone from companies that sell the sieve and it is a fraction of the cost of the finished product (~$20 vs. ~$100+).
What does the additional $80 pay for?