AplusChoice via eBay offers this Reverse Osmosis 5-Stage Water Filter System for $88.90 with free shipping. That's tied with our mention from two weeks ago and the best deal for this model today by $8, excluding the below mention, and the lowest price we've seen for any reverse osmosis water filter system. It filters up to 50 gallons of water per day and can be attached to the kitchen tap or installed under the sink. Features include quick-connect fittings, a 3.2-gallon water storage tank, water pressure gauge, and faucet.

A close price: Yescom via Amazon offers it for $89.99 with free shipping.