You can register for anything and everything, as long as there's a price variety. A registry is a list of suggested items, people aren't bound by it, and they will buy you things you didn't register for. If I saw a $400 crib on a registry, I wouldn't bat an eyelash, unless every other item was over $100, that would annoy me.
Put everything on there and use the completion coupon to buy any necessities that your shower guests didn't purchase for you. You'll probably recieve gift cards as well, which you can combine on a purchase of a big ticket item.
I suggest searching around several stores including overstock and amazon for nursery furniture, you might score a much better deal than target/BRU. If you find a great sale price on an item from your registry, buy it yourself and remove it from the list.