It all depends on what kind of connections your recording equipment has. If you have say a standalone DVD Recorder with RGB SCART connection (hey, you’re in the UK so seems possible) you could hack up a simple cable at less than 10, but if you need S-video or composite for connecting to a computer-based capture card an encoder like the $70 JROK will be required. Obviously you will also need a microphone to record audio outside of the game.
I think it’s JRok’s encoder I was going to get for my cab. I was trying to set my cab up so that my HDTV takes video using Component cables. That way if we’re playing a 4-player game, I could hook up two sticks using either extension cables or wireless, two can play from the HDTV, 2 from the cab.