Lucky you! I can't wait to have chickens one day - they're so cute, bimbling around the place.
It depends how many you have room for, I would say. There one of those things that are a bit addictive
My ex-boss had maybe 3 or 4 layers, and sometimes we had enough eggs and sometimes none. My outlaws have about 8 chickens and a couple of ducks, and through the summer they have enough to give us lots, but in winter they sometimes still end up buying eggs. Since there'll always be people who will happily take eggs off of you (they're great for trading for small things, actually), maybe it's worth looking at the space you're willing to give them and going from there?
Good luck in your chickeny adventures