My tnk was $175 used and $25 to fill it, I think the Auto Pilot was about $160 on Amazon, Titan regulator was $100 and the "Laser" drilled holes was $25. I keep think Laser is the name of the person in China with a drill but there are no burrs so that may be true. I am sure I could have shopped around and go a better deal. They say C02 works the best from early to a little past mid flower, I wanted the system to help the plants in the hotter months. 

We will see, my RDWC plants are in the beginning of flower and the 3 plants in the Ebb & Flow are at mid flower and had started showing a little sign of foxtailing