I would say that a moses basket is handy when baby is very small, but not a necessity. Mine cost �5 from a charity shop and was in excellent condition and was a total godsend. Have a look on Ebay as there are usually bargains on there for things like travel systems / prams, etc.
All babies are different and my friend swears by those battery operated swinging chairs and she gave me one she was no longer using but my little girl has probably been in there for a total of about 20minutes in two months! Her little boys will sit in one for hours and doze off. Because my daughter doesn't seem that bothered by toys I have been buying them second hand on Ebay and you can save lots of money that way.
I think you will find that when baby is born you will be given loads of clothes - my little one is 3months now and I have only bought her about 2packs of sleepsuits that I bought when I was pregnant. When she was born we were given a baby bath, bags of clothes to take her up to 2 years old, baby books, nappies, baby toiletries, etc, from people who had had babies themselves and were no longer using them.
Oh, and instead of buying sheets specifically for moses baskets you can use pillow cases, and I can't afford cotbed size sheets right at the moment but I have loads of single bed sixe sheets so am using those and tucking them right under the bed.
My biggest tip though is to start buying early; what I started doing on my weekly shop at Tesco was buy a packet of nappies (various brands and sizes), or wipes, or teats or sleepsuits - something small and reasonably cheap (around �5 per week). As long as you check the use by date you could probably do this with formula milk too, unless you're breastfeeding of course!
Ummm.... and lastly, Primark so lovely soft blankets REALLY cheap. Everyone has commented on my soft and fluffy blankets and they were about �2 or �3 from Primark.