The XPath expression to use would be `//span[contains(text(), ' Estimate ')]`.

You can fetch all matching elements in JavaScript using the following snippet:

```js
// Iterator over all span elements that contain ' Estimate '.
const iterator = document.evaluate("//span[contains(text(), ' Estimate ')]", document, null, XPathResult.UNORDERED_NODE_ITERATOR_TYPE, null);
```
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