Although I have not made a practice of checking every Wal Mart I have been in, I don't remember ever being in one that did not have the plugs. Unless you live near an RV store Wal Mart would be my first stop.
Brian, Loretta & Lucy (Golden Retriever)
2008 HR Endeavor 40 PDQ , ISL 400
2010 Dodge Ram 1500 Toad