Here are some useful websites/stores I like to buy cats’ supplies:
Chewy: They have plenty of promotions like ” Buy $100 can get a $30 Gift Card”. And they have great customer service.
Amazon: If you have Amazon Prime, it is a great choice for you to get supplies in two days. Sometimes, they have promotions like “Buy $100, get $30 off”
Petsmart: You can find Petsmart easily in each city.
Petco: Same as Petsmart, shopping online will have extra discounts.