Erm
By DS4 my list went .....
Nipple cream - lansinoh - bit pricey but three years on still using it to protect chaffed noses in winter
Sling - I liked the old fashioned baby bjorn but defo personal taste .... I had a big baby though so it could fit in
Nappies and Wipes and defo nappy bags.
Babygrows and vests with popper bottoms ... Invested 16 in 0-3 months and 8 next size up.
Baby sleeping bag.
Carseat
Baby bouncy chair - got a cheap one.
A list of baby classes and post natal activities that I'd signed up for.
No muslins, no prams, cots, Moses baskets, monitors, sterilisers, bottles changing bags etc. Didn't have any hand me downs as he was a bonus child. Invested in other bits as I needed them. So got bottles at 16 weeks but sterilised in dishwasher. Got cot at 5 months when DN handed it on - he slept in our bed and in a drawer initially. I wore a lot of scarfs to hide my tum and provide BF prviacy that served as muslins for mopping. I just washed them frequently and made sure I used a white bit if needed. Changing bag was a small cross body bag from topshop that fitted wipes, couple of nappies and a change of clothes in. As I had to traipse around after 3 older boys I was keen to travel light.
That said I needed more stuff for PFB. For DS1 I had more clothes, muslins, a baby bath, pram and, most importantly, the "what to expect" baby book as it was all a bit of a shock 
Congratulations. It's such a wonderful, challenging and enlightening thing being a parent. I wish I could have another 