sorry ghds are the winners through and through. However I do believe it depends on your type of hair and the water in the area you live!
I have very curly hair and live in an area with hard water., so there are only ghds that can handle my hair.
However when I go on holiday and the water is soft I am able to use my Tesco value straighteners that I bought for �7 and they work exactly the same. and plus, if I lose them whilst on holiday I really dont care!
If you havent got loads of hair or really curly/frizzy hair, then any good make should suffice (my mate has some she bougth for about �50 and they do her hair fine)