A five to 10 GPM RO/NF membrane system, along with the ancillary equipment (you might add about another $10k with tanks, pumps, and things like that), the system could be about $45,000 to $60,000 for a small, commercial-quality unit.When you get into higher industrial qualities, you can double or triple that cost, whereas a 30 to 50 GPM commercial-quality …Web