页面源和检查元素没有相同的数据

From time to time I like to use php to grab some data using cURL.

Typically, I will use a particular link, and get the source of the page, then isolate the text I am looking for, and save it to my MySql database.

In this case, there is a value I am trying to get at. In the source, I see:

 <input type="hidden" name="hdnOrignalEstdValue" id="hdnOrignalEstdValue" />

which does not have the value.

But in the 'Inspect Element' console I see this:

<input tabindex="0" value="1768000" name="hdnOrignalEstdValue" id="hdnOrignalEstdValue" type="hidden">

This inspect element console sees the "hdnOrignalEstdValue" field, and shows the value (which you can see looking at the web page after you navigate to the link)

I have scoured the source code, and checked every link, and looked at the code for every related link, but the "1768000" can't be found anywhere. Since I see it showing up under 'Inspect Element', I know it is being delivered to my computer somehow, but I don't know how to code php, and/or use a different version of cURL, or some other method to 'find' that number.