Baby clothing help.

My baby is 1 month old & I have lots of 0-3 month clothing

My question is, is it worth it to get 3-6 month clothing as well? I’m confused about sizing tbh.

Should I just get 6-9 months?

Never realized how expensive buying baby clothes can be for the 1st year 🫣

Edit - I’m talking about only footed sleepers. Not investing in pants or shirts. Baby is gonna live in sleepers until at least a year 🤣