I have considered buying a soil test kit since I send in soil samples every year for testing. The problem with all the small test kits, is that they only test for pH, Nitrogen, Phosphorus and K, Potash. They do not test for calcium, which is a key nutrient for ginseng.
To get a kit that would include the test for calcium, costs around $350 on up. Unless there is some cheaper way to test for calcium levels alone, its just not worth the bother for a test that is incomplete.
perhaps there is someone on here that knows how to do a cheap test for calcium.
It cost me $12 for each soil sample I send in to the University of Maine. But is a very complete and accurate soil test.