Yesterday I bought carnation flowers in a pot for 400 yen ($3.92 €2.84) at Tops on the day after Mother's day. Mother's day has already gone, so it was sold with discount price. I think the original price was around double of the discount price.
The hamster in my house ate leaves of carnation when the hamster found them in the room. The hamster is still alive now. It seems leaves of carnation do not have deadly poison for hamsters.