Just curious which one would have been more cost-efficient for your family, specifically?
Breastfeeding for us meant: Renting a hospital grade pump ($60 a month) necessary to help establish supply in the beginning, and then efficiently pump at work every day, bra milk collecting shells, nipple shield, nursing bras, disposable nursing pads, hands free pumping bra, bottles that fit on the pump, extra pumping supplies, manual pump, Mother's Milk Plus Special Blend ($30 for one month supply), domperidone prescription ($125/month), oatmeal, LC appointments, Boppy, My Brest Friend.
Formula: Enough samples that we didn't have to buy any for a long time and came in ready-to-feed bottles. Formula is provided by our daycare at no extra cost.
It would have been wayyyyy cheaper for us to formula feed. Currently we do a 50/50 combo.