Product Price and Cart Price Incorrect - double discount?

[Elizabeth_Chris]

store is www.ringcrush.com 

Recently added and tested four apps - all Free Gift / cart upsell apps like

-GA: Free Gift | BOGO

-Cart Upsell+Free Gifts Monster

-EasyGift: Auto Add to Cart

-CartBot

i reached out to app developers for help but in meantime any help from the community is appreciated.

is it best practice to duplicate a theme before testing apps? Or any other bug prevention techniques?