I have some GHD's and i really recommend them! they are really good and your hair stays straight all day instead of waving after a few hours :)
I got mine from my hairdressers that sell them and they weren't that cheap :S
Look around on some sites - maybe ebay?
Good luck and i hope you fine some - i love mine
I have Kodo straightners. Several of my friends have GHDs and prefer that when we go holidays etc I take mine. We all find them to be great and are half the price of GHDs. I have had mine for about 4 years but my friend recently got some new ones and they are just great too. We got ours from www.ukhairdressers.com