I'm planning on buying a 50acre plot of land just outside my city strategically located in a spot I think the city will need to expand to in a few years to a decade. Right now it's $150k. If I got it subdivided and dug out rough foundation holes (I can operate excavators, loaders, tandem trucks/semis/5-tons, skidsteers, etc), I want to then stockpile the soil and clay to resell to construction companies (it has value in large enough quantities).

Is buying land and stockpiling raw materials like dirt, clay, gravel, etc a bad idea? I have a feeling the price for those will go up with all the carbon taxes, gas/oil taxes, etc that are creeping up