Not at all, without checking my reciepts im not 100% but im sure I used
http://www.rallydesign.co.uk/index.php?cPath=85_248
the fittings are the dearest part but as long as you get the right ones its not too much, like I say Im not sure if these are the cheapest now, I did it 4 or 5 years ago and they were. Someone might know somewhere cheaper, theyre a piece of piss to assemble though so dont fret on that part.