How many milk storage pouches?

I am due in April and plan to use Kiinde breast milk storage pouches so I can pump right into them. Since they are a little more expensive I've been stocking up as I get good deals or coupons.

My question is, how many will I need? I don't want to have too few and have to buy them at full price and I don't want to have a bunch of extras that I wasted my money on. Can anybody give me a ballpark and guess of how many I will need?

I plan to feed breast milk for the first year with a mixture of both directly breastfeeding as well as bottle-feeding pumped milk.