Buying Dog food with coupons

I just got back from WinnDixie.  Here is an example of getting the most for your money:  I had 2 coupons for Mighty Dog dog food.  $1 off 6 cans.  I also had a store coupon for 1 free when you buy 10.  These cans were on sale for 60 cents each.  But I found them packaged in 2 for 1 boxes.  So I bought 12 cans (24), got twice the cans for the same cost, plus saved an extra $2.60.  If I had bought them at regular price with no coupons, I would have paid $16.80 for 24 cans.  Instead I paid $4.60 for 24 cans.
Did I NEED Dog food today???? NO  If I had waited until I needed dog food I might have had to settle for regular price, and so I never let that happen.  This food doesn't expire until 2014--2 more years.  I have enough food for about 2 months.  So i will continue looking over the next month and keep my eyes open for more bargain opportunities.  The only thing I don't buy this way is milk.  I buy it because I need it--sometimes I get a good deal at CVS--best place to buy milk because they sell Barbers and it is same cost as a store brand and sometimes you get bucks back.