yeah - you can get a set for around £300ish on ebay or the likes of. You also need a few other bits and bobs, such as new connections and the likes of - totals around £45. Then the fitting. It's possible to DIY, but you'd need to cut the wings a little bit and this puts off quite a few peeps (certainly me!).
As stated, they will pass an MOT, but they are still not legal. I guess thats similar to a lot of things, speeding, not declaring a mod etc etc. I guess the main concern is making sure the alignment is correct and that you do not blind oncoming users.
Note my costings there do not include washers and self levelling system, which I dread to think how much they would cost!
Hope this helps a bit!
Rob /ubbthreads/images/graemlins/laugh.gif