Buying Coupons In Bulk

There are times where I buy lots of the same product for example Totino's Party Pizza. My whole family loves these and we go through about 3 a week. I purchase these coupons through ebay. I get about 15-20 coupons in one order. I always look for the expiration date before I purchase because I want to be able to use them before they expire. Second I always look for the best coupon and price. Example: In most cases for this pizza coupon it either is buy 3 and get $.50 off or buy 5 and get $1.00 off. For me since my supper market doubles the $.50 coupons I look for the buy 3 and get $.50 since off because I know it will double to a $1.00 off.