Eye waterningly expensive, but also a good long game play if you're growing large volumes of small plants with faster turnover. Be aware multi-tier systems are complex, require meticulous planning, and are just one of the many considerable expenses in multi-tier growing systems, including high LED lighting costs, circulation, power, HVAC, and more. There's also a good argument in favor of four-tier over three-tier. Two-tier systems are not recommended.