Was the tank swap cheap? No! This is for the Rainbow vacuum cleaner. This vacuum cleaner is not cheap. Did it work great? Yes! My kid ran my Rainbow without water and the original tank melted. After I stopped crying I went to Revane to see if there was a replacement. Hallelujah, that was it. And as far as the cost of replacing the tank compares to the cost of a full vacuum, it's cheap. It is the same as the original. I am happy, the child is happy that I did not have to ground him for a yearβ¦