Try the supermarkets for some good bargains - Sainsburys had some nice nursery bedding sets in the other day for a good price. Maybe wait for the Jan sales as well?? I can't decide about getting a cot bumper - opinion on whether or not they are dangerous seems to be divided.
I got a fab crib set on ebay that had a bumper, duvet, sheet and blanket for £10. After a wash it looked brand new. We are on a tight budget too so know what you mean. xx