@cardboard33 DS lived in sleepsuits for the first three months of his life, whether out in public or not. Outfits - in my opinion! - seemed too much fuss and not comfortable enough for a sleepy little baby. Not sure about multipacks of leggings - I got given a load secondhand from friends - but JoJo Maman Bebe do a reasonable deal on very good quality leggings - 2 for £15. Still expensive though for a tiny, fast-growing baby, but might be nice to have a couple of pairs!
In terms of layers, DS was born in a v hot July but he had issues with his body temperature dropping due to blood sugar crashes, and I ended up having him in a short-sleeved bodysuit underneath his sleepsuit a lot of the itme for the first couple of months. If March / April are cold then I'll be doing the same again!
You will probably find you are given a lot of newborn / 0-3 month clothes anyway, so you just need to make sure you have enough essentials. You can always send DP out / order online to get more if you find you haven't got enough. Sizing is a bit difficult - DS was 8lbs 12oz and never fit in any of his newborn stuff, a lot of which was only up to 8lbs. I will get half a dozen newborn or 'up to 1 month' things for the first couple of weeks - I can always get more if I need to. And then I will make sure I have about a dozen sleepsuits and a dozen bodysuits for 0-3 months, plus a couple of cardigans. Scratch mitts are crap; they just fall off. Look for the sleepsuits that have the fold-over cuffs that you can use to tuck their hands inside while they are sleeping. (Also, if you breastfeed, I found the fold-overs very useful to keep scratchy little nails away from my sore boobs.)
You'll probably change their outfit at least a couple of times a day due to sick / wee leaks / poonamis. Depends how sicky your baby is though! If the clothes aren't dirty, don't change them! I also found I was changing my top a couple of times a day, because I was either vomited on or because I had leaked through my breast pads. You probably won't just be doing one wash a week any more... I was definitely doing one a day. But then I had Cheeky Wipes as well, so was washing those.
This is making it seem very real, ladies 