How many bottles?

Li

Hey all you moms with little ones that still remember the baby stage! I am looking at bottles and I'm wondering how many bottles do you like to have? I was thinking 9? We'll have to do dishes, clearly, but I want enough that we're not constantly washing bottles to make one. What's a good number of bottles to have? And is it really necessary to have 4oz AND 8oz bottles or would starting out with 8oz work just as well?