Populating Custom Fields from live JSON

I’m a bit confused by how the code relates, but here’s how I would work with the data in the provided screenshot.

This is looping through the data array and accessing the quoted USD, if it exists.

I’m adding the prices to an array by the object’s ID just to give you an example.

$prices = array();
foreach ( self::$remote_data['data'] as $data ) {
    if ( ! isset( $data->quote ) || ! isset( $data->quote->USD ) ) {
        continue;
    }
    $prices[ $data->id ] = $data->quote->USD->price;
}