Unfortunately babies need lots of stuff. I started as soon as I found out my babies gender. That gives me time to chase down the bargins.
I like to have enough clothes to keep me going for the first 12 weeks. Those first 12 weeks can be quite an emotional and physical transition.

Your baby is due at a great time because the weather will be perfect! Because your baby will be in mostly summer clothes, now would be a good time to check out the post summer sales. (All the winter stuff is starting to fill the shops, and you probably won't need too much of that)

One thing that I think is pretty unnecessary is a change table. I've had them - and hardly ever used them. So that is one thing you can put to the bottom of your 'to get list'.

Have you considered checking out second hand / preloved baby stores or garage sales for the things you need? They often have loads of baby stuff at a fraction of the original price.

Op shops used to be a good option too, but I have heard they can be a bit pricey these days.

Just remember to wash second hand baby stuff in an antibacterial wash. (Nappy san for whites, and/or canistan antibacterial wash) I don't think thats the right spelling - but it will give you an idea.

If your totally against the idea of second hand and have a tight budget. Maybe make a list starting in order of priority. That will save you from waisting money on the things you dont NEED.

Good luck.