Purina Tidy Cats Breeze Pads - Pack of 10

Anyone else notice that you can pay about $3 per pad on amazon or half that on target? plus target has free ship on 25. what a let down.

how come this says Pack of 4 in the picture?

Is there a significant difference between these pads and training pads for dogs? They look the same to me.

how often should you change out these pads?