Como utilizar "Is", "Are", "One", "Ones", "This", "Those" e "These"

Minha dúvida é se preciso usar o "one e ones" em alguns casos e outros não. Tipo: "How much is this blouse? (How much is this one?)" ou "How much is that t-shirt? (How much is that one?)"
Aqui usei o nome do objeto e o "one".
Vi no plural que não se usa o ones: Como: "How much are these pants? (How much are these?)"
"How much are those rings? (How much are those?)".
Posso usar? Tipo: "How much are these?" E "How much are these ones?"
How much are those e How much are those ones?
Ou é melhor só usar "How much are these sneakers?" E "How much are these?" E "How much are those cars?" E "How much are those?" Sem o ones
Obrigado.