We did that for my house for a while. It wasn't too expensive, just a couple million a month (after initial one-time costs like buying equipment and building t

We did that for my house for a while. It wasn't too expensive, just a couple million a month (after initial one-time costs like buying equipment and building the physical plant on a couple of neighboring acres). But in the end, factoring in plant maintenance and all the employees that it required, my family decided it would be more cost effective to just have weekly shipments of bottled gasses from a scientific supplier.