15 nursing bras, though!! I don't think most people would shell out that much :)
(You would have to buy bras anyway - whether bf or ff. )
You don't need branded bags or bottles - and if you're ff you'd have to buy bottles!
24 breastpads are not needed - I used old hankies that belonged to DH.
You absolutely don't need pregnacare supplements. If you want to use supps, then of course you can do so, but ff might use these, too.
Clothing - you have to wear something when you ff, too :)
No one needs a pump. I hand expressed, though I know not everyone finds it easy.
You'd need to subtract what you would buy anyway, unrelated to bf (clothes), then subtract the unnecessaries (branded bags, supps) and then consider if the other stuff is useful or necessary.
Bf can be virtually free, and as you say on your blog, ff expenditure on the milk, bottles and teats and sterilising stuff goes on.