What's the point of having a nursery?

Hey Ladies, 
So I am 26 weeks and have been looking into starting the nursery with hubby. We have the space (spare bedroom) but don't have the $ moola. It's just been tough on us lately financially. Now push come to shove I think we can make it happen but lately I'm wondering what's the point? Why panic and stress to make sure this nursery is ready on time for baby when he's gonna stay with us for at least 6 months anyway? What are your thoughts on this? Moms who are co-sleeping for the first few months or so, why have the nursery ready before baby is here as oppose to closer to when they will actually sleep there? thanks for your opinions!!