var obj = [
 {name: 'a1', type: 't1', price: 10},
 {name: 'a1', type: 't1', price: 10},
 {name: 'a2', type: 't2', price: 10},
 {name: 'a1', type: 't2', price: 10},
]

[
 {
  name: 'a1', type: 't1', price: 20
 },
 {
  name: 'a1', type: 't2', price: 10
 },
 {
  name: 'a2', type: 't2', price: 10
 }
]