Making your own can result in much nicer curtains than ready made ones - which are often made abroad and that's why they're cheaper. It all depends, if you can manage the initial cost, they are something that you may be living with for many years. There are companies that specialise in roll ends and clearance fabrics, like Just Fabrics in Burford, but although they are a lot cheaper than the RRP some of them can still be quite expensive. You can often pickup curtains on Ebay at very good prices and it may be worth a look.