I haven't read the rest of this thread, but was just having this conversation with DH the other day and these are the things we came up with, which we wish someone had told us not to bother with...
Nappy wrapper - cartridge costs about £5 and only lasts a week and you do not end up with little sausage shaped nappies they lead you to believe!!
Sling - worn for an hour three mornings running when DD was newborn (just over 8lb, so not really a heavy baby) and got really bad back ache so never got used again.
Cot bumper - apparently shouldn't be used until 6 months and DD didn't go into her cot until 6 months anyway, but then shouldn't be used when baby is sitting up and DD was sitting up by 6 months - complete waste of money.
If breastfeeding and planning to express electric breast pump instead of manual. we bought a manual one and ended up buying an electric one after 3 months - if you get a good make you can then sell it for a good price on e-bay afterwards!
Car seat that attaches to the pram. sounded a great idea to move her from car to pram without waking her up, but just not practical. We did it twice when she was first born and it was just too heavy to carry around and awkward getting it in and out of the car. would have been better off getting just a car seat. and newborns shouldn't be in car seat for longer than 1 hour at a time anyway so by the time you've driven whereever if you leave them in the seat whilst shopping for example and then they are in it for the drive home - it's well over an hour.
Blender for making purees!!! if you wait until 6 mths to wean and then do BLW absolutely no need for a blender (ours is still in box untouched, wish someone had told me this!)
Cot bedding - we got loads before DD was born and she didn't go in her cot until 6 months and now just has a sheet over the matress and wears a gro bag - maybe we will get some use out of it further down the line, but totally unnecessary so far!
Travel arch for the pram - just got in the way when trying to get DD in and out of the pram and annoyed me. currently on car seat and still annoying me.
Think that's it - HTH and good luck with pregnancy/birth!!