My wife and my daughter bought a hamster potty for 287 yen ($2.74 €2.10) at Daishin. The potty is too small for our golden hamster to use it. I do not know why they bought such a small potty. It is useless. The hamster has never used it.
Sand for hamster potty = 166 yen ($1.58 €1.21)
My wife and daughter also bought a pack of sand for 166 yen ($1.58 €1.21). They put sand into the potty.