How can I say this to my guests without sounding rude?

I am working on my registry for my baby shower. I know how people get when there's a baby to buy for. They like to skip the registry and just buy cute clothes and stuffed animals. My husband and I are working really hard on this registry and would really like guests to stick to it. We also already have tons of things that I started buying throughout my pregnancy and even before I got pregnant. Also, we could really use some help with the larger items, so I want to somehow mention that, although we would appreciate anything anyone decides to give us, we would appreciate it even more if maybe a group of people got together and pitched in on one of the bigger items, rather than each of those people buy a couple outfits or blankets. Does that make sense? I just don't want to come across as rude or ungrateful.

*I forgot to add, i wouldn't put it on the invite or anything, and I wouldn't tell every person, just really close family and friends. I was thinking maybe mention it to my mom and mother in law, and let them mention it to siblings or something? I don't know. I'm not expecting everyone to even bring a gift, just that if they choose to, please stick to the registry.