Water filtration system

I-spring RVC7P-AK 6-stage superb taste, high capacity, under sink, reverse osmosis drinking water filtration system with alkeline remineralization and natural PH. Other systems like this range from $300-$500. This unit is slightly used but then we had to move. Kids have moved out, new place is smaller..... So no room. Unit is as-is.... Is in great shape though. Best to have plumber install unless you are handy.