Yes, you can buy a reverse osmosis system for the price of a fancy dinner for two. These countertop models are the gateway drugs of water purification—small, cute, and almost useless for a family of five. Expect to spend about $150 to $200 for a basic under-sink unit that installs with the grace of a drunken squirrel.
Here’s the twist: these cheap systems often require you to replace filters every three months. That’s like buying a $20 car that needs a $200 oil change every Tuesday. The water is clean, but your bank account will develop a slow, emotional leak.
