I would take advantage of the deal. Just tell your family and friends you already have a carrier and stroller. I waited to buy every thing I bought until after my shower tho, which I'm very glad I did because I was going to buy myself a diaper bag and ended up getting 3 of them at my shower haha!
I would take advantage of the sale towards the end. Just do not out a stroller or carrier on your registry and you should be fine. My husband and I waited until our shower to buy what we needed. Honestly, we did not spend any money out of pocket and our son got everything he needed with the gifts purchased and the large amount of gift cards we received. Do you know if family will purchase big ticket items? I am sure you can always get store credit if someone buys you one.
I know my parents are getting the crib and bedroom set cause its their tradition on my side. My mother in law has just been buying the odd ball stuff my husband wants but we really wont need... Lol i still laugh some times.. But not really sure what everyone would be willing to buy.. My sister wanna do hand-me-downs. All the way from when i was little..My girlfriend said she help out with a pricey item but she didn't specifically say which. But she has twins herself and i told her with her plate being so full i dont expect her to go all out cause i know shes very tight with money as is.
I think it really depends on your social/family situation. If you've got a big group of friends and a large family that each person will probably spend $30-40 on you, then I'd say you can wait until after the baby shower to go baby shopping. If you have a small circle of friends and an average sized family then I wouldn't expect to get everything you want/need for baby. I'd also be careful about adding tons of stuff to your registery if you have a small group so that people don't feel bad if they can't get everything.
We moved cross country when I was 10 weeks pregnant and I don't have many friends here yet. I did an Amazon registery for family who wanted to send things but I just put items that would be nice to have. We bought all the must haves and had everything by 28 weeks because we were on a budget and bought deals when they popped up.
I waited until my baby shower and most people brought clothes and nothing big except I got 2 car seats. Which was the only thing I had already bought and told people not to buy. Thankfully I returned them and bought things I actually needed.