JSFiddle - React, Tailwind, and code Playground

HTML

<div class="item">
  <span class="count">2</span>
  x
  <span class="price">20</span>
</div>
<div class="item">
  <span class="count">1</span>
  x
  <span class="price">20</span>
</div>
<div class="item">
  <span class="count">2</span>
  x
  <span class="price">60</span>
</div>

JavaScript

const items = [
	{id: 'id1', price: 10},
  {id: 'id2', price: 20},
  {id: 'id3', price: 30},
  {id: 'id4', price: 40},
  {id: 'id5', price: 50}
]

const arr = ['id1', 'id1', 'id2', 'id3', 'id3'] // count id1: 2, id2: 1, id3: 2, price: 100

const filtered =  items.filter(item => arr.includes(item.id))

console.log(filtered)

const totalPrice = filtered.reduce((acc, el) => acc + el.price, 0);

console.log(totalPrice)