Escaping $ When Calling do_shortcode

I am using wp-rss-aggregator to display RSS feeds from several sites. In a normal page the plugin behaves as expected. However, when calling echo do_shortcode(“[wp-rss-aggregator source=$feed_id]”) inside [insert_php] tags, any text starting with $ (like dollar amounts) are cut off to the first delimiter. An example would be $2,000 would be display as ,000.

Do I need to run call it with an str_replace in there somewhere to escape the $ characters or something?

Thanks in advance for the help.

https://wordpress.org/plugins/insert-php/