When we built our house, it was a chemical farmers corn fields. Of course the developer took all the top soil and took it right down to the rock and clay hard pan. The first year I was ready to grow and realized with a low harvest I needed to go another route. What we ended up doing was building a long raised bed. 4 feet deep by 125 feet long. To this I added coconut coir, green sand, sweet lime and other amendments. Well, it should come as no surprise that I could not produce enough
compost for such a large area so we ended up gathering all the free manures we could find from local horse owners.
In the end, we moved that raised bed around until now 18 years later I have a garden plot that is 50 feet deep and 125 feet long that produces some of the deepest colors, richest flavors and amazing yields. Sometimes when we look at our land we think it is too large to tackle to bring it back into a "circle of life" state of healthy being. Through the years we purchased rabbits which we raise for their cold fertilizer and chickens who will scratch and keep everything light and fluffy (just fence them out when actively growing). If we lived on a large enough plot for a cow, goat or pigs we would have incorporated them into the whole equation. Bottom line, if you can't afford the testing, build "above" the ground and a good base on top of what you have will incorporate a healthy below ground soil in the end.
Edited to add this:
A "live" soil is far more productive than a dead soil. Micro nutrients are a healthy by-product of a living soil, getting that way can take a few years, but from my own personal experience with poor "dead" soil to my "live" soil where the only things I add are the products of the compost pile (no additional amendments are needed any more).....we have been healthier, with more energy. Not only is there a link to healthier "live" soil with healthier plants....but when we spend all that time making the "base" of our life healthier, we start looking at making the rest of our lives healthier as well. From how we preserve our crops to how we prepare foods that go in our mouths. We are what we eat, and we are what we eat, eats.