Now that's a good buy!

For a while now I've been keeping track of sale meat prices. I use this card twice a week when the ads come out (Hyvee on Sunday, the rest on Wednesday) to know whether there's a good sale on meat. 

  

If I find a lower price, I mark out the old price and note the new lower price. 

 

Based on my card, Checkers in Lawrence has a really good deal on Boston butt pork roast this week. 99 cents a lb. Previously I had only found it as low as $1.48 lb. 

What else should I keep track of? Flour and sugar prices? Laundry detergent?