Dialing Down: Cat Litter

I feel like I have the cost of many things in my life "dialed down" pretty well, but I'm also always looking for ways to save.  I have a cat named Ivy that is...a bit princess-y in some ways, especially considering that she is from a shelter.  She is a frequent bathroom goer and a little bit obsessive to boot, so we have settled on pine litter as being the best option for her issues and for me since it absorbs odor and is generally less disgusting than regular litter.

                                          The furry one 

For years, I bought Feline Pine brand litter and then switched to the Petsmart generic to save a little bit.  Feline Pine is 9.99 for 20lbs at Petsmart and 11.99 for 20lbs at the local grocery store.  The Petsmart generic is $9.99 for 25 pounds.  I recently became aware of the fact that pine litter is the exact same thing as plain pine horse stall pellets, but the horse pellets are significantly cheaper.  WHAT??

I took my booty on over to Orscheln Farm and Home two weeks ago to investigate further, but they were completely out due to a sale.  On Monday, I went back to find the pine horse stall pellets in stock AND still on sale.  The sale price was $5.49 for 40lbs, and the regular price is $6.29 for 40lbs.  SHUT THE FRONT DOOR!!!

Here's the math:
Feline Pine at Petsmart      49.9 cents per pound
Feline Pine at Grocery       59.9 cents per pound
Generic FP at Petsmart      39.9 cents per pound
Pine Horse Pellets              15.7 cents per pound
Pine Horse Pellets (sale)  13.7 cents per pound

How did I not know this (years) earlier?  I know this is ridiculous, but oh how it makes me happy when I figure out a new way to save!!!