The basic aquastar system cost around $600+. Each module to add into the function will cost between $300-$600. These add up a lot of the cost.
Say you want a system to monitor pH, conductivity, redox, temp, water level, 2 socket bar for timer and 2 socket bar for wave making. The total cost will add up to around $4.4k. If you like to measure oxygen and pressure, that will be another 1k down the drain