Few points from experience:
(1) Ask your parents if they have anything spare, even one fork and one spoon is better than nothing. My parents had some old pyrex dishes (they were my grans, so 50 years old lol) which they let me have.
(2) I agree with spreading out the buying. I was lucky enough to find some comfy and pretty duvet covers, bedding etc. in the sale from M&Co. When I bought all the essentials for cooking from the Tesco value range with a printer it cost me £200 so that's a rough guide. I also went to car boots and bought egg cups from Jerusalem for 50p, some photo frames and I also met someone who did the same course as me and I bought some of her old books.
(3) To be honest, you won't be starting studying officially for at least a week and by that time your student loan would've come through. If money is short then buy essentials like stuff for cooking, bedding etc. Leave buying books until you're at uni and you have your syllabi for that year - in my case a lot of the syllabi changed and the books we use change every week so some of the books I've bought I haven't helped me on my course. Amazon marketplace and ebay are also good for buying books and ask if there are any second hand bookshops. I know for philosophy there is a list of second hand book shops in London so similar searches may be of use. If you can buy anything, I would recommend a printer (with as few ink cartridges as possible and cartridges which are cheap to replace like Kodak). My halls also had a sale on the first day of things which the previous residents left behind so I managed to buy a plastic tower storage unit on wheels, some books relevant to my course, an alarm clock etc for 50p-£1.50 each.
(4) Last thing to consider is transport. Do you have enough room to carry everything? Things like duvets etc. can take up a lot of room.