Own brand nappies and wipes, or any products you use regularly that are on BOGOF.
Dont bother with babybath, babypowder, baby lotions etc.
Accept donations of clothes etc from friends and family. From age 0-6 months they will only wear some things a few times before outgrowing it.
If you are going to buy outfits, adn you plan on having more children - buy neutral colours and avoid pinks/blues so they can be re-used for siblings, irrespective of gender.
Buy a 2nd hand pram system but invest in a good stroller - it will last far longer and be more durable than a pram.
Dont buy special bowls, spoons, blenders, bottle/food warmers, storage pots for weaning. If you are going to puree foods - mash with a fork or sieve, and freeze in standard icecube trays.
You dont need a steriliser - just wash in hot soapy water, rinse and air dry bottles - or wash in a dishwasher if you have one.
Always buy the best breast pads, not the cheapest. They will work better, less likely to irritate, and less likely to show through clothing.
Start an account up with ebay