Random selection of the things we bought and didn't use:
Baby bath - I put her in with me
Pram, pushchair, travel system (yes, all 3! all good ones but from ebay). Am too lazy to faff around with them and just bung her in a sling as I find it a lot less hassle. They're not actually mandatory, I was amazed to find!
Changing bag. now have cheapie rucksack as easier to carry.
Clothes. Mostly we got these free but DD seems to have managed with about 3 babygros and 5 vests at any one time, plus a jacket and snowsuit and woolly hats. I've only just started putting her into actual "clothes" at 6 months and then not very often. We were given enough stuff to clothe a small country and used a fraction of it.
Cot and moses basket bedding. Then we got given a couple of sleeping bags and all she needs are two bottom sheets.
Bouncy seat - a cheapy. Never really had on occasion to use it. Might have done if it had music and lights.
BF tops. Tried and failed - gone for the vest with no sleeves under normal tops option.
and for the birth - disposable maternity pants, nursing nighties - wish I hadn't bothered as I just ended up using old knickers and a stretchy normal nightie - I kept clipping the night bra onto the nightie by mistake in the wee small hours and nearly garrotted myself when getting changed on more than one occasion.
Calpol, infacol. Not all babies get sick! Depends how far you live from a chemist of course...
DD only got her "own" room a month or two ago as we wanted somewhere we could keep the dog out of (she sleeps under our bed). Not for that it would probably still be a fair way off. Needless to say, it has not been redecorated and the furniture is all second hand and very cheap/free from ebay/friends. Suspect she hasn't even noticed yet!
Good luck - hope it all goes swimmingly!