Baby Bottle Question

I’m due with my first child soon and have a question regarding baby bottles. Is it necessary to start off with the smaller 4oz style bottles as opposed to the larger 8/9oz bottles?

I plan to purchase glass and given the price of them, I’d rather get my moneys worth and purchase only the larger size since I know I’ll get more use out of them long term.

Is that a silly question to ask? I just don’t see the point in buying the smaller size if they’re only used for the first 3 months or so, but maybe I’m missing something.