The amount of time they spend (30-35 hours a week plus help from family and dedicated rooms), the amount of money they save (must admit this is often more than a part time job at minimum wage), and what they actually buy (massive amounts of crap food most of the time) do not make it worthwhile IMO.
I seriously think most of those women need some help for a mental issue and I would be far more impressed if they and their families looked fit and healthy.
Admit I'm a little Rainman about grocery prices, but that lets me stock up on staple food items on sale that I normally buy - bacon, chicken, cheese, pasta, laundry detergent, soup etc.
100 bags of croutons, an entire display basket of aspirin, more items than the supermarket register can handle - that is excess and waste, not thriftiness.
Though it is pretty cool to see them pay $20 for all the carts of crap.