I agree with cordelli -- 30-Minute Meals is much more helpful. I think $40 A Day is more contrived. It's nice to see some of the places they go on the show, but overall is boils down to the same formula each time: go to nice places at lunch, and you'll save; try the specials; ask the locals. No new info there.
I will confess to being something of a 30-Minute Meals junkie. I make sure TiVo gets it every day. Sometimes she's got some really good ideas, and I appreciate that she maintains the spirit of the show quite well -- she's not relying on tons of pre-prepped stuff to make a fancier meal in 30 minutes than she should really be able to. I think it's pretty legit, doing mostly her own chopping right there and such.