Yes coway/cuckoo all those are totally unncessary. Unless you have a big household, say 7-10 people and are in constant need of hot/cold water and totally can afford it.

Barang dapur means kitchen foodstuff, like raw ingredients, onion, veges, etc.

Makan means eat out. This is a realistic expectation, as most family will have a few session of eating out. Just because need to budget, doesn't mean they won't eat out. Sometimes they are just too tired after work or shopping, hence will eat out.