I have the 6 liter one, I think it cost about $80. A tip I learned on youtube, depending on what you are cleaning, if you want to use a more caustic agent such as gasoline or solvent or simply want to avoid having to drain and clean the tank you can isolate the item in a plastic bag or glass jar with the solvent and just fill the tank with clean water. It will work just as effectively as it would without the isolation container.