If you have a Shark floor cleaner and you are not constantly tidying up your floor, keep about EIGHT of these on hand, use them for cleaning one time (or even one area), then wash them according to directions. (Note that if you use warm water and dry them on low, they WILL shrink).
I have a 13-yr-old male Jack Russell terrier and two teenage boys. I have a 3 story "town home" (built 2007) and the main floor is all wood, including the kitchen. What I usually end up doing is spot cleaning (note old JRT), then I do a rough vacuum of the entire floor, THEN I take the Shark floor cleaner and use one pad for the kitchen, one for the dining area, and one for the living area. In a perfect world I would do that once a week.
I suspect that one pad gets 20 uses before it gets COMPLETELY disgusting. Do the math as far as cost.
Note, I don't even bother with the Sanipads...