Quick take
Basic countertop RO often starts around $300–$500. Premium hot/cold units can reach $800–$1,000 or more. Budget for proprietary cartridges every year.
Entry and midrange systems
Waterdrop and JIMMY offer countertop RO products in the few-hundred-dollar range, often with UV, hot water or other appliance features.
Premium systems
RKIN U1 adds chilled water, hot water and other features, pushing the hardware price much higher than a simple countertop purifier.
Annual cartridge cost
Countertop systems usually use proprietary multi-stage cartridges. A lower upfront price can be offset by expensive or frequent replacement filters.
Renter value
For renters, the ability to move the system can justify the premium versus a permanently installed under-sink unit.