The simplest under-sink RO systems, the ones that do the job without any bells or whistles (or fancy faucets), start around $150 to $300. Think of these as the reliable Toyota Corolla of water filters—they get you from A to B, but the cup holder doesn’t glow in the dark.
You’ll find brands like APEC or iSpring in this range. They usually include a standard storage tank, a few basic filters, and a simple chrome faucet. The catch? Installation is on you, unless you pay extra for a plumber. And trust me, that “extra” will make you miss the simple days of just buying a Brita pitcher.
Pro tip: check if your local hardware store has an open-box return. I once snagged an RO system for $80 just because the box had a dent. The water tastes exactly the same as the $300 version, I promise.
