The cost is a rather embarrassing £20k. The biggest cost is the circuit boards about 7 or 8k now I think. The simple hardware such as the aluminium, nuts and bolts etc was a few thousand. Cables and connectors were thousands. I've had to get 300m of ribbon cable so far and its not going to be enough ! There's about a thousand connections. The proper electronic components transistors/resistors/LEDs not as dominant as you might expect. There seemed to be just an endless amount of stuff that was needed.